Cardiff School of Sport
DISSERTATION ASSESSMENT PROFORMA:
Theoretical / Conceptual
(Including: Desk-Based, Secondary Data, Meta-Analysis) 1
Student name:
Adam Smith
Programme:
SES
Dissertation title:
Supervisor:
Student ID:
ST10001461
Effects of playing surface and gender on rally durations in singles grand slam
tennis.
Lucy Holmes
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CARDIFF METROPOLITAN UNIVERSITY
Prifysgol Fetropolitan Caerdydd
CARDIFF SCHOOL OF SPORT
DEGREE OF BACHELOR OF SCIENCE (HONOURS)
SPORT AND EXERCISE SCIENCE
EFFECTS OF PLAYING SURFACES AND GENDER
ON RALLY DURATIONS IN SINGLES GRAND
SLAM TENNIS.
(Dissertation submitted under the discipline of
Performance Analysis)
ADAM SMITH
ST10001461
NAME: ADAM SMITH
STUDENT NUMBER: ST10001461
CARDIFF SCHOOL OF SPORT
CARDIFF METROPOLITAN UNIVERSITY
EFFECTS OF PLAYING SURFACES AND GENDER
ON RALLY DURATIONS IN SINGLES GRAND
SLAM TENNIS.
Cardiff Metropolitan University
Prifysgol Fetropolitan Caerdydd
Certificate of student
By submitting this document, I certify that the whole of this work is the result of my
individual effort, that all quotations from books and journals have been
acknowledged, and that the word count given below is a true and accurate record
of the words contained (omitting contents pages, acknowledgements, indices,
tables, figures, plates, reference list and appendices).
Word count:
Date:
9,613
19/03/2013
Certificate of Dissertation Supervisor responsible
I am satisfied that this work is the result of the student’s own effort.
I have received a dissertation verification file from this student
Name:
Date:
LUCY HOLMES
CHANGE THIS DATE
Notes:
The University owns the right to reprint all or part of this document.
Table of Contents
ABSTRACT ................................................................................................................................. xiii
CHAPTER ONE .............................................................................................................................. 1
Introduction ................................................................................................................................. 1
1.1 Background .......................................................................................................................................... 1
1.2 Rationale for Study ........................................................................................................................... 2
1.3 Aim of the Study ................................................................................................................................. 2
1.4 Delimitations of the Study .............................................................................................................. 3
1.5 Limitations of the Study .................................................................................................................. 3
CHAPTER TWO .......................................................................................................................................... 4
Literature Review ...................................................................................................................................... 4
2.1 Literature Review ............................................................................................................................... 4
2.2 Playing Surface Effects ................................................................................................................... 4
2.3 Tactics and Strategies ..................................................................................................................... 7
2.4 Physiological Aspects ..................................................................................................................... 9
2.5 Psychological Aspects ................................................................................................................. 10
CHAPTER THREE ................................................................................................................................... 12
Method ........................................................................................................................................................ 12
3.1 Research Design ............................................................................................................................. 12
3.2 Participants ....................................................................................................................................... 12
3.3 Playing Surfaces ............................................................................................................................. 12
3.4 Instrumentation ............................................................................................................................... 13
3.5 Pilot Test ............................................................................................................................................. 14
3.6 System Development .................................................................................................................... 14
3.7 Procedure of Data Collection..................................................................................................... 15
3.8 Reliability ............................................................................................................................................ 16
3.9 Data Analysis .................................................................................................................................... 16
3.10 Operational Definitions. ............................................................................................................. 17
CHAPTER FOUR ...................................................................................................................................... 18
Results ......................................................................................................................................................... 18
CHAPTER FIVE ........................................................................................................................................ 22
Discussion ................................................................................................................................................ 22
5.1 Discussion ......................................................................................................................................... 22
5.2 Rally Data ........................................................................................................................................... 22
5.3 Set Data ............................................................................................................................................... 26
5.4 Impacting Factors of Extraneous Variables ........................................................................ 28
CHAPTER SIX .......................................................................................................................................... 31
Conclusion ................................................................................................................................................ 31
6.1 Conclusion ......................................................................................................................................... .31
Refernces .................................................................................................................................................... 32
APPNDICES
Appendix A
List of analysed matches. ..................................................................................................... A-1
Appendix B
SPSS Outputs ............................................................................................................................ B-1
List of Tables
Table 1 Operational definitions of key performance indicators………………17
Table 2 Comparisons of rally durations for men and women singles at three
Grand Slam Championships………………………………………………………...23
Table 3 Comparisons of number of shots for men and women singles at
three Grand Slam Championships…………………………………………………24
Table 4 Rally durations across sets for men and women singles……………24
Table 5 Number of shots per rally across sets for men and women singles….
…………………………………………………………………………………………….25
Table 6 Wimbledon roof effects on rally data for men and women singles...26
List of Figures
Figure 1 Graphic representation of tennis ball types and their rebound
properties…. .................................................................................................. ….11
Figure 2 Men and women’s template panel for data collection……………...19
Acknowledgements
I would like to thank Lucy Holmes who supervised this study. The process of
completing this study was greatly improved both with her guidance and advice as
well as her openness in regards to discussing the best way forward in the data
collection phase and then the subsequent write up. Her help throughout the year
has been greatly appreciated.
Thank you.
xii
ABSTRACT
xiii
The techniques and tactics implored by elite tennis players have seen substantial
changes over the past 20 years (Sanchez-Munos et al., 2007). As a result, many
studies have observed how rally durations vary across the different types of
playing surface and produced ramifications for the athletes and their tactics.
Therefore the purpose of this study was to assess the effects that both the gender
of the athlete and the court surface had on rally length in three of the professional
grand slam tennis tournaments. Secondly, to assess whether any differences
regarding rally length within a match exist, and to highlight the extent of variation
between sets. Data was collected from thirty matches (n=30), 15 men’s and 15
women’s, spread evenly across three of the tennis Grand Slam tournaments
(French Open, Wimbledon & US Open). Dartfish EasyTag iPhone application
(Dartfish) was used for data collection from video coverage of each individual
match. The match variables analysed rally duration in seconds (s) and the number
of shots that each rally contained. Results indicated that men have continued to
have a greater length of rally than women on clay and hard courts, however
women saw a longer rally duration when playing on the grass courts of
Wimbledon, but fewer shots were played. Significant results were found when
comparing both rally duration and number of shots across the three playing
surfaces (p<0.01), with clay showing the longest rally duration and grass the
shortest. Interrogation of the within match variables, identified that within the
men’s game the rally duration as well as number of shots decreases gradually
from set 1 to set 3, with an increase being seen in set 4 & 5, however caution
needs to be taken with these results due to the amount of matches analysed.
Women saw set 2 produce the longest rally data, with set 1 & 3 showing similar
results. In conclusion, matches played on clay have continued to see the longest
rally durations and most number of shots for both genders, with grass producing
the shortest durations and least amount of shots. Differences were seen between
genders with men producing longer rallies on clay and hard courts and women on
grass, yet men were seen to play the most number of shots on all playing
surfaces.
xiv
CHAPTER ONE
Introduction
1.1 Background
Many studies have been conducted within racket sports and more specifically
tennis. Hughes (1994) showed that performance analysis can be undertaken that
can provide an evaluation of a player’s movements, tactics, and technical game
aspects and finally facilitate statistical compilations. This is essential with regards
to tennis specifically as Sanchez-Munos, Sanz and Zabala (2007) found that
tennis performance over the past two decades has seen substantial changes with
regards to technique and tactics, as well as the changing physical performance
aspects that are required of the players. Furthermore, as athletes seek the ‘total
package’ to perform at a peak level, both physical and psychological skills are
required, as well as fitness and injury prevention (Gould and Eklund, 1991).
The game of tennis can be played in a singles match, a contest between two
players, or a doubles match, between two pairs of players. Each given match
consists of a series of points that form a game, with a number of games forming a
set, and finally a collection of sets forming a match (Douglas, 1992). Importantly,
men play a best of five set match at Grand Slam Championships, with women
contesting a best of three set match. Four Grand Slam Championships are
contested throughout the calendar year, with one being played on clay, one on
grass courts and two contested on hard courts.
Tennis playing surfaces and the varying playing aspects that they produce has
widely been analysed. O’Donoghue and Ingram (2001) found that court surface
influences the length of rallies in Grand Slam singles tennis events. Previous
studies (Richers, 1995; O’Donoghue and Liddle, 1998; Takahashi et al., 2006)
have analysed the time factors of rally length, as well as the amount of shots
played per point. The conclusions of these studies state that clay is known to be
the slowest of the courts, producing the most shots per point, and grass being the
fastest surface consequently producing fewer shots per point.
1
1.2 Rationale for Study
As previously stated, past literature has investigated rally durations and shots per
point for past Grand Slam Championships. However, this type of analysis has not
been undertaken recently, therefore resulting in knowledge of how rally durations
and number of shots per point have developed over recent years not being
known. During this time many changes have been seen within the modern day
game of tennis that could have effects on rally lengths. These changes include
the changing physicality and mental requirements of both the men and women’s
game, the adaptation to the newly implemented tennis balls and most recently
the new roof over centre court at Wimbledon. Previous studies have also focused
on the men’s game within tennis and as a consequence the women’s game has
largely been ignored. Therefore there is scope for analysis on the women’s
duration of rallies and shots per point.
A new development within the realms of Grand Slam tennis is the implementation
of a roof over the centre court at Wimbledon. No research has currently been
published on the effect that the roof has on rally durations and shots per point for
neither the men’s nor women’s game. This therefore is a new area of research,
that is applicable to the modern day game of tennis and could help the players
and their respective coaches understand the changes that are seen when the
roof is in use.
1.3 Aim of the Study
The study aimed to see the effects that both the gender of the athlete and the
court surface has on rally length in three of the professional Grand Slam tennis
Championships. Furthermore, to identify whether any differences exist between
rally length within a match and how it may vary between sets. Finally to see if the
newly implemented roof over centre court at Wimbledon affects the rally lengths
produced.
2
1.4 Delimitations of the Study
Matches that were available from the public domain were chosen to be analysed.
Only complete matches were included in the study, as incomplete matches could
skew the set data results. Data analysis was only undertaken on rally durations
and the number of shots per point, resulting in all other aspects of the player’s
performance being ignored.
1.5 Limitations of the Study
Possible limitations of the study include the amount of analysed matches. With
only five matches for both men and women being analysed on each of the three
surfaces, only 30 matches in all were analysed. With the knowledge that each
Grand Slam Championship contains 127 matches for each gender, only five of
those matches would have been analysed. Furthermore, only matches from the
second week of the championship, round four onwards, were analysed. This
created a pool of players that were higher in skill level and therefore produced a
distorted picture of the wider professional tennis circuit. It also resulted in many
players being repeatedly analysed, possibly skewing the results of the study
towards the playing style of those given players. A further limitation was the
amount of matches analysed under the roof at Wimbledon. With only one
complete match being analysed for both men and women, the true effects of the
roof could not be distinguished.
3
CHAPTER TWO
Literature Review
2.1 Literature Review
Many studies have been conducted within racket sports and more specifically
tennis. Hughes (1994) showed that performance analysis can be undertaken
which can provide an evaluation of a player’s movements, tactics, technical game
aspects and finally facilitate statistical compilations. This is essential with regards
to tennis specifically as Sanchez-Munos et al. (2007) found that tennis
performance over the past two decades has seen substantial changes with
regards to technique and tactics, as well as the changing physical performance
aspects that are required of the players. Furthermore, as athletes seek the ‘total
package’ to perform at a peak level, both physical and psychological skills are
required, as well as fitness and injury prevention (Gould and Eklund, 1991).
2.2 Playing Surface Effects
The playing surface of which the game of tennis is played upon can have a
significant effect on the performance of not only the ball, but also the players
(Blackwell, Heath and Thompson, 2004). The International Tennis Federation
(ITF) have categorised the speed of the court into five different categories.
Category 1 is known as a slow court, category 2 will be a medium slow court,
category 3 will play a medium speed, medium fast speed is category 4 and finally
the fast courts are category 5 (ITF, No Date).
.
With regards to movement on court Ferrauti, Weber and Wright (2003) found that
80% of all strokes were played within 2.5m of the player’s ready position. A
further 10% of shots were made with 2.5 - 4.5m of movement, with predominantly
a sliding movement being utilised, and less than 5% of stokes were made with
greater than 4.5m of movement and a running movement. In relation, Richers
(1995) predicted that a player can be expected to complete explosive efforts up
to 600 times within a match, requiring repetitive movements throughout. With this
in mind, Girard, Eicher, Fourchet, Micallef and Millet (2007) further found that a
surface with a higher friction increases the speed of the game but can also
potentially lead to more frequent injuries. This is due to players being required to
4
perform at an increased rate of acceleration, speed, torque and hyperextension
resulting in a greater potential of muscle fatigue and injury.
Court surface further has an impact on the player’s potential for injury. A study
conducted by Girard et al. (2007) suggested that when players were on clay
courts, a lower frictional resistance was produced which leads to a substantially
decreased muscle force and loading around the joints, resulting in a reduced risk
of lower extremity injuries. Additionally, injury rates in professional male tennis
players have been analysed. Bastholt (2000) compared player’s injury treatment
on clay, hard, grass and carpet covered courts. The study found that during
match play, injury treatment was required most frequently on grass surfaces and
significantly more often on hard courts than that on clay. Results concluding that
risk of injury are increased when playing on grass and hard courts than when on
clay courts
Extensive research has been undertaken in relation to the effects that the playing
surface has on rally lengths. O’ Donoghue and Ingram (2001) found that court
surface influences the length of rallies in Grand Slam singles tennis events. They
concluded that clay courts produced the longest rallies and grass courts
produced the shortest rallies. This is further backed up by Richers (1995), who
found that average rally times were 4.3 ± 2.7s on grass and 7.6 ± 6.7s on clay for
elite tennis players. Additionally, O’Donoghue and Liddle (1998) found that
average rally times from matches in 1996 were 5.64 ± 4.69s at the French Open
and 3.69 ± 2.54s at Wimbledon and finally Takahashi et al. (2006), who showed
that the average number of shots per rally was 5.5 ± 4.4 shots at the French
Open, 3.7 ± 2.8 shots at Wimbledon, and 4.5 ± 3.8 shots at the U.S. Open.
These studies conclude that clay is known to be the slowest of the court surfaces
and grass the fastest of the surfaces. This knowledge allows players to therefore
adopt different strategies on the differing playing surfaces. Takahashi, Wada,
Maeda, Kodama and Nishizono (2009a) concluded that playing at the French
Open players tend to adopt a defensive baseline strategy, allowing for rallies to
take place, in contrast this, whilst playing on grass and hard courts players opt for
a more aggressive approach aiming to make the points shorter.
5
However, the game of tennis has seen a decrease in the overall length of rallies.
Takahashi et al. (2006) found that rally length times became shorter from 2003 to
2004. Further stating that players during that time required greater anaerobic
power, due to the shortness of the points, in terms of duration and shots, as well
as the increase that was seen in ball velocity. This can be linked to the findings
that the serve and serve return are regarded as the most important shots in
tennis (Furlong, 1995; Pestre, 1998; Unierzyski and Wieczorek, 2004).
Furthermore, Furlong (1995) studied the role of the serve in both men’s and
women’s tennis, resulting in service being claimed to be more important in the
men’s game. In addition, O’Donoghue and Brown (2008a) stated that men served
significantly more aces and service winners than women, therefore resulting in
service becoming a more important aspect within the men’s game. With the
knowledge that service is important in the game of tennis, O’Donoghue and
Ingram (2001) discovered that aces and service winners were more frequent at
Wimbledon and the US Open than at the French Open. They further stated that
games with high percentages of aces and service winners were also the games
that had the lower rally durations.
As the men’s game of tennis has further emphasis on the serve, this could be
linked to the reason that men generally have lower rally durations compared to
women. O’Donoghue and Liddle (1998) confirmed that women’s singles has
longer rallies than that of men’s singles matches. O’Donoghue and Ingram (2001)
produced figures on rally length, with results showing women had mean rally
lengths of 7.1 ± 2.0s compared to that of men at 5.2 ± 1.8s. However,
O’Donoghue and Brown (2008b) have claimed that rally length in men’s singles is
increasing at all four of the Grand Slam tournaments since 1999. Whereas
women’s singles rally length has decreased at all of the tournaments bar
Wimbledon. This could suggest that service is becoming less important in the
men’s game and longer rally durations, similar to the women’s game, is possible
in the future.
With tennis being played in repeated points, resulting in a ‘stop-start’ sport, the
athletes need to be able to recover quickly after each point. Kovacs (2007)
defined tennis match play as intermittent anaerobic exercise bouts that vary in
6
intensity, that include numerous rest periods over a prolonged period of time that
therefore allows the aerobic energy system to aid the recovery process.
Esbjörnsson-Liljedahl, Bordin and Jansson (2002) observed that during three 30s
sprints male’s power output decreased from sprint one, in contrast to the females
who did not. This would suggest that women tennis players will generally be able
to produce a greater power output consistently throughout a game. A point
backed up by Billaut, Giacomoni and Falgairette (2003) who found that women
have demonstrated a higher rate of recovery following high intensity exercises.
As a result women’s rally length may be longer due to the ability to recover after
each rally, whereas men may struggle to recover after a longer rally the previous
point.
2.3 Tactics and Strategies
With rally durations changing, it can be linked to players producing strategies
prior to playing their opponent. Over and O’Donoghue (2010) have stated that
weaknesses of the opponent should be targeted, whilst not allowing them to
utilise their strengths. According to Unierzyski and Wieczorek (2004) almost all
professional players employ tactics that allow them to open the court as soon as
possible, putting an opponent in a defensive position, resulting in aggressive
tactics dominating modern day tennis. Additionally, top level players are said to
have achieved ‘tactical automation’ allowing them to be more efficient in decision
making, resulting in a more defined, consistent and clear game pattern (Piles and
Crespo, 2012).
An aspect within tennis that affects strategic choices and rally length is the tennis
ball. The ITF has recently introduced three different types of ball with the
knowledge that the pace of the court is affected by the friction that occurs
between the ball and the court surface. During contact with the playing surface,
the greater the friction between the ball and the surface the greater amount of
ball speed will be lost, therefore resulting in a slow surface. With lower friction,
the ball speed will be greater, resulting in a faster playing surface (Miller, 2006).
The new balls are therefore implemented to equal the speed of play across all
7
three types of court. The type 1 ball is used for a faster speed of play; in contrast
the type 3 balls are used to decrease the speed of the game, compared to the
speed of the game when using the type 2 ball (Blackwell et al., 2004). Miller
(2006) details the differences within the ball types as the type 1 tennis ball is
harder and more resistant to compression than the standard type 2 balls. As a
result the type 1 ball is recommended for slower speed surfaces such as clay. In
comparison the type 3 ball is 6 - 8% bigger than that of the type 2 balls, but
identical in other aspects. As a result of this, the type 3 ball is used for faster
surfaces due to the ball slowing down the speed of the game by creating a
greater air resistance, producing deceleration on the ball as it flies through the
air.
Figure 1. Graphic representation of tennis ball types and their rebound properties.
8
2.4 Physiological Aspects
An athlete’s gender will always be a factor that affects sporting performance
whether it is through the impact of height, weight, body fat percentage, aerobic
capacity or anaerobic threshold as a result of genetic and hormonal differences
(Sparling and
Cureton, 1983; Maldonado-Martin, Mujika and Padilla, 2004;
Perez-Gomez et al., 2008;). Within a game of tennis it was found an athlete can
be required to hit approximately 1000 shots and run 3km (Weber, 2001). This
requires the athletes, both male and female to be physically fit. Smekal at al.
(2001) concluded that a player’s physical fitness can be used as an asset that
could make the difference between success and failure during tournaments.
The physiological demands of the players can vary extensively dependent upon
their playing style and tactics. Bernardi, De Vito, Falvo, Marino and Montellanico
(1998) compiled a study looking at a college tennis tournament and how a
player’s style and tactics affected the length of the point. It was found that
attacking players, who were in control of the rally, resulted in an average duration
of point in 4.8 ± 0.4s. If the player in control was a whole-court player the average
duration increased to 8.2 ± 1.2s. Finally, a baseline player that was in control of
the rally increased the average further, resulting in an average duration of 15.7 ±
3.5s. The results of this study show that with different playing styles and tactics
the physiological demands for that player to cope and recover also change.
A key aspect within the difference of rally length between genders is also the
length of match they play. In Grand Slam Singles tennis, men play a best of 5
sets match, whereas females play a best of 3 sets match. This therefore results
in different physical and mental strains put upon the athletes during play.
With game imposed breaks between points, games and sets it culminates in a
high amount of rest periods throughout a match in which a player can utilise
recovery processes. Reilly and Palmer (1995) conducted a study to find the
exercise to recovery ratio of top club male tennis players. They concluded that
the exercise to rest ratio was 1:2.5, which is similar to that of Chandler (1990) as
cited in Reilly, Hughes and Lees (1995) who collected data from the 1988 US
9
Open Men’s singles final, therefore suggesting insignificant differences between
elite and non-elite players.
2.5 Psychological Aspects
The outcome of the match is dependent on not only the player’s physical skills
and talents but also the psychological skills of the players (Richardson, Adler and
Hankes, 1988). Hanin (2000) further emphasises this premise by highlighting the
need for an athlete to have the ability to control and manage their emotions in
order for them to achieve optimal performance, tying in with Moran (1995) who
suggests the athletes could find difficulties in not letting their attention wander
during matches due to the untimed and ‘stop-start’ nature of tennis match play.
With looking at elite performers Gould, Dieffenbach and Moffett (2002) suggested
that they have a greater self-confidence, improved concentration, control arousal
levels effectively, utilise better psychological skills such as goal setting and
imagery and have higher levels of motivation and commitment.
Within such long durations of matches momentum swings back and forth with
‘turning points’ throughout the match. Morris (1979) stated that critical points are
played within tennis games which results in the outcome of that point having a
greater influence on the final outcome of the match. Richardson et al. (1988)
found that 21 different factors affected a player’s momentum. These factors
included holding or breaking of serve, with twice as many players citing breaking
of serve more important rather than holding serve, as well as winning long
games, becoming more aggressive and gaining consistency in a favourite shot.
Psychologically players perceive that winning key moments increases the
probability of success in the match, therefore leading them to believe they have
gained psychological momentum and thus psychological advantage over their
opponent (Richardson et al., 1988).
Weinberg, Richardson and Jackson (1981) investigated the effect of winning the
first set and how that momentum affects the end result. The study was an
archival study of over 2,000 matches and summarised that 86% of male players
10
who won the first set ended up the victor, 73% coming in straight sets. In
comparison, 91% of females who won the first set won the match, with a further
82% being in a straight sets win, clearly suggesting that winning the first set
swings momentum in favour of the winner of that first set. As momentum cannot
be calculated or verified, looking at rally length could indicate how a longer length
of rally, both psychologically and physically, affects the player and the
subsequent points that follow.
As no research has looked at how rally length has developed over the recent
years, this study will aim to look at if rally length has changed in recent years on
the three tennis playing surfaces, clay, grass and hard courts. As well as this,
data will be collected for both men and women’s tennis. With this, it can then be
compared across genders to see the differences, also allowing the data to be
contrasted with previous rally length studies to see the progression of rally length
in recent years.
11
CHAPTER THREE
Method
3.1 Research Design
The study aimed to see the effects that both the gender of the athlete and the
court surface has on rally length in three of the professional Grand Slam tennis
Championships. Furthermore, to identify whether any differences exist between
rally length within a match and how it may vary between sets. Finally to see if the
newly implemented roof over centre court at Wimbledon affects the rally lengths
produced.
3.2 Participants
The required data was collected from matches played at the 2012 French Open
(clay), Wimbledon (grass) and US Open (hard) championships. The data was
extracted from videos that were available in the public domain.
Data was
collected from the second week, round four onwards, from each championship.
This enabled for a pool of players who had won three consecutive matches to be
available, therefore decreasing the chance of matches that resulted in a one
sided performance resulting in more closely contested matches to be analysed.
From each championship, five matches from the men’s draw and five from the
women’s draw were analysed at random. Each match was analysed for the full
duration; men’s a best of five set match and the women’s a best of three set
match. In total, fifteen (n=15) matches were analysed for both the men’s and
women’s game, resulting in thirty (n=30) matches in total, evenly distributed
across the three playing surfaces at the differing championships. In all, 70 - 75
hours of play was analysed.
3.3 Playing Surfaces
The International Tennis Federation (ITF) have categorised the speed of the
court into five different categories. Category 1 is known as a slow court, category
2 a medium slow court, category 3 a medium speed, category 4 a medium fast
speed and finally the fast courts are category 5. (ITF, No Date).
12
With more specific detail on each surface it is known that Wimbledon is sown with
100% Perennial Ryegrass and has been since 2001 and cut to a height of 8mm,
dating back to 1995. Both these aspects help with the durability of the court over
the tournament period. The bounce of the ball is largely determined by the soil,
not the grass, which needs to be hard and dry to withstand the requirements of
play (Wimbledon, No Date). Regarding the French Open, it is played on a court
that has three layers, one of limestone, clinker and stone (French Open, No
Date). Finally the US Open is played on a category 3 surface produced by
DecoTurf (California Products Corporation, Massachusetts, USA).
3.4 Instrumentation
Dartfish EasyTag iPhone application (Dartfish) was used in the data collection
alongside video coverage of each individual match. The EasyTag application
allows for notational analysis to be used by Apple products. The application
enables a timer to run throughout the analysed match, alongside a fully
customizable tagging panel that is utilised to time-stamp the key performance
indicators of that given sport. EasyTag’s panel can contain from 9 to 30 buttons
each of which can be set to time stamp a fixed, user-defined duration which
allows a single button tap to record an event. Buttons can also be set to be open
duration which is ideal for recording the length as well as frequency of phases of
play. Finally the application displays instant statistics of the frequencies of each
event (Apple, 2012). In this case, the application was used to collect data on rally
duration in seconds (s) and also the number of shots that each rally consisted of.
3.8 Reliability
A pilot study was conducted to check both the reliability of the system used to
collect data, in this case the developed system using the Dartfish EasyTag
iPhone application (Inter reliability), and also the reliability of the operator using
the developed system (Intra reliability). This resulted in both inter and intra
operator agreements being found by implementing Kappa analysis. For this,
Operator A had to complete two separate analyses of the same performance
allowing for the intra operator agreement to be found and the reliability of the
13
observer to be assessed. Operator B completed a single analysis, which was
used alongside the first analysis by Operator A to find the inter operator
agreement and the reliability of the system.
3.5 Pilot Test
The pilot test involved two independent analysts watching an identical set of
tennis from the 2012 Australian Open Women’s single final between Victoria
Azarenka and Maria Sharapova. For each analysis both the duration of shots (s)
and the number of shots in each rally were analysed. The data was then inserted
into a devised excel workbook that produced kappa values. Kappa values were
used as this eliminates the chance of operators guessing throughout the analysis.
The reliability results showed 1.00 for both intra and inter operator agreements
when analysing the number of shots in the rally. Using Altman’s (1991) scale,
both results show perfect reliability for both operator and system being used. For
duration of shots, intra operator agreement was 0.86, whereas inter operator
agreement was measured at 0.79. This resulting in intra reliability scoring very
good on the scale produced by Altman (1991) and inter reliability being ranked as
good reliability.
3.6 System Development
Through testing and use of the devised system from both pre and post the pilot
study, the panel and system that was developed changed to allow data to be
collected more efficiently and effectively.
Subtle changes took place prior to the pilot study. One of these being changes to
the wording of some buttons. Rally and rest buttons were developed at first, but
through use it was clearer to the user to change these to start and end buttons.
This would enable observers who had not used the system previously to clearly
understand the use of the buttons with both having clear parameters. A further
small change was the colour scheme of the system. At the beginning stages the
system did not have a specified colour for any of the categories of buttons. It
14
became apparent that a colour scheme for each category (Sets, Games, Duration
and Number of shots) would make the system easier to use and more effective in
that less mistakes would occur by pressing the wrong button.
The final change was the introduction of a fault button. The fault button was used
in the data collection whenever a service fault occurred or a fault within the point
occurred such as the umpire making a decision to replay the point. Prior to the
introduction of this button, the end button would have been used. When analysing
the data on excel it would then become difficult to understand whether or not the
observer had forgotten to push the number of shots that occurred after pushing
the end button or if a fault had occurred. The fault button was then developed into
the system and enabled these problems to be eradicated.
3.7 Procedure of Data Collection
The Dartfish application allowed for a panel to be designed for the data collection.
For both the men’s and women’s collection panels a six by five grid was used. All
30 buttons were used for the men’s panel, whereas the woman’s consisted of 29.
Five red buttons for the men’s template (Set 1, Set 2, Set 3, Set 4 and Set 5) and
three red buttons for the women’s template (Set 1, Set 2 and Set 3) were used to
distinguish the set that was currently taking place. A further green button was
implemented to signify when a new service game was due to start. Three blue
buttons were used to designate when a rally had started, ended and whether a
fault had occurred on serve or during the point being played, such as the umpire
making the decision to replay the point. This produced a time value from when
the start button was pressed to when the observer signified the end of the rally,
resulting in the rally duration in seconds (s). The final yellow buttons, 1-21 for the
men’s panel and 1 - 22 for the women’s, were used to designate how many shots
were played throughout that given rally.
This procedure took place throughout the entirety of the match and produced a
chronologically ordered list of events that was exported into Microsoft Excel.
15
Figure 2. Men and women’s template panel for data collection.
3.9 Data Analysis
The data produced was initially entered into Microsoft Excel during data
collection, allowing for averages and standard deviations to be calculated. After
this process, data was exported into Statistical Package for the Social Sciences
(SPSS) for Windows. This program would therefore allow for numerous statistical
tests to be under taken on the chosen variables. A Mann Whitney U test was
used to compare the data within the two genders. A Kruskal-Wallis test was used
to test for differences between the three playing surfaces analysed. A Friedman
test was used to compare results between sets within the matches that were
analysed.
16
3.10 Operational Definitions.
Table 1. Operational definitions of key performance indicators.
Definition
Rally Start
Rally End
Number of
Shots
Description
Beginning of rally was designated as when the server had
made contact with the ball during their service motion.
Ending of the rally was either signified by a second bounce of
the ball, the first bounce when hit outside the boundaries of
the court or when the ball was hit into the net.
Classified as successful shots. Shots that land outside the
court boundaries such as attempting a return winner that
lands outside the court boundaries will not be counted.
17
CHAPTER FOUR
Results
Results
Table 2. Comparisons of rally durations for men and women singles at three
Grand Slam Championships.
Rally Duration (s)
French Openᵃ
Wimbledonᵃ
US Openᵃ
Men
8.8 ± 6.9
6.4 ± 5.3
8.0 ± 7.4
Women
7.4 ± 4.8
6.6 ± 5.3
6.9 ± 5.0
s = seconds, ᵃ = Significant result between three playing surfaces (p <0.001)
Both men and women were found to have the longest rally duration when playing
on the clay courts at the French Open, with both genders having the shortest rally
duration on the grass courts of Wimbledon. Rally duration at both the French
Open and US Open were longer for the men, whereas women rally durations
were longer in comparison to men at Wimbledon. Men saw a greater range
between the French Open and Wimbledon (2.4) with women showing only a 0.8
difference. A strong difference (p = .161) was found between the men and
women’s data across the three different tournaments for rally duration. Table 3
shows a similar trend of results as Table 2, with men and women again having
the most amounts of shots per rally when playing at the French Open. Similarly,
both men and women rallies consisted of the least amount of shots when playing
at Wimbledon. The men again showed a bigger difference in the amount of shots
per rally from Wimbledon to the French Open (1.5 shots) in comparison to that of
the women (0.5 shots). The difference between the men and women shots per
rally was found to have a strong difference (p = 0.112) across the three Grand
Slam tournaments. For both rally duration and the number of shots per rally, a
significant difference (p <0.001) was found to exist when comparing the surface
that was played upon against one another.
18
Table 3. Comparisons of number of shots for men and women singles at three
Grand Slam Tournaments.
Number of Shots
French Openᵇ
Wimbledonᵇ
US Openᵇ
Men
Women
5.8 ± 5.1
4.3 ± 3.9
5.3 ± 5.3
4.7 ± 3.4
4.2 ± 3.7
4.6 ± 3.6
ᵇ = Significant result between three playing surfaces. (p <0.001)
Within Table 4 is the data regarding the average rally durations for men and
women’s singles for each set and how they differ throughout a match. Men were
seen to have the longest rally durations in the 5th and last set, however, this result
must be taken with extreme caution as only two of the fifteen matches analysed
resulted in a 5th set being played. With men playing at least three sets within a
match it is important to see how they differ. Set 1 shows a greater average with a
gradual decline taking place between set 1, 2 and 3. Set 4 shows a slight
increase, and with nine of the fifteen matches consisting of a 4th set it can be
deemed applicable to the Men’s game. Women saw a greater average rally
duration in the 2nd set, with set 1 and 3 showing the same rally duration. Must be
noted that nine of the fifteen analysed matches consisted of a 3rd set. A
significant difference (p ˂0.001) was found to exist between men and women’s
rally duration between sets, with men showing a longer duration of rally in
comparison to the women. The number of shots per rally represented in Table 5
follows the trend that is shown in Table 4. This is as expected as it is assumed
that the longer the duration of rally the greater amount of shots will be played. As
such, men again saw the most amount of shots in the 5th set, but as stated
previously only two matches consisted of a 5th set. Men otherwise saw the 1st set
consist of a high average with a steady decline of 0.3 shots over each of the next
two sets. The 4th set increased slightly from the previous 3rd set. Women’s singles
matches saw the 2nd set consist of the most number of shots followed by set 3
and finally set 1. In comparison to the men, women saw a smaller range between
19
each set, with a significant difference (p ˂0.001) being found when compared
against one another.
Table 4. Rally durations across sets for men and women singles.
Average
1st Set
2nd Set
3rd Set
4th Set
5th Set
Men
7.7 ± 1.6
8.0 ± 2.1ᵈ 7.7 ± 1.5ᵈ
7.3 ± 1.5ᵈ
7.5 ± 2.0ᵈ
8.8 ± 1.7ᵈ
Women
6.9 ± 1.2
6.7 ± 1.2ᵈ 7.1 ± 1.4ᵈ
6.7 ± 1.2ᵈ
-
-
ᵈ = Significant result between set rally durations (p <0.001)
Table 5. Number of shots per rally across sets for men and women singles.
Average
1st Setᵉ
2nd Setᵉ
3rd Setᵉ
Men
5.1 ± 1.1
5.4 ± 1.4ᵉ
5.1 ± 1.0ᵉ
4.8 ± 1.1ᵉ
Women
4.5 ± 0.8
4.3 ± 0.8ᵉ
4.6 ± 0.9ᵉ
4.4 ± 0.8ᵉ
4th Setᵉ
5th Setᵉ
4.9 ± 1.4ᵉ 5.9 ± 1.3ᵉ
-
-
ᵉ = Significant result between set number of shots per rally (p <0.001)
Table 6 shows the effect that the Wimbledon roof has on rally duration and
number of shots per rally for both men and women’s singles. Of the ten analysed
matches, one complete match under the roof for both men and women was
analysed, as well as a further set and a half for men and half a set for women.
Therefore the results must be taken with caution.
Men produced a shorter
duration and fewer shots per rally when the roof was open. With the roof closed,
the men saw rally duration increase by 0.9s and 0.7 more shots being played on
average when compared to when the roof was open. The women saw increased
rally duration and an increased amount of shots per rally with the roof open. With
20
the roof closed women rallies were 1.8s shorter with on average one shot less
being played on average. The roof therefore was found to have a contrasting
effect on the men and women’s game, with the roof having a bigger effect on the
women’s game.
Table 6. Wimbledon roof effects on rally data for men and women.
Men’s
Duration (s)
Men’s No. of
Shots
Ladies
Duration (s)
Ladies No. of
Shots
Average
6.4 ± 5.3
4.3 ± 3.9
6.6 ± 5.3
4.2 ± 3.7
Average Roof
Open
6.0 ± 5.2
4.0 ± 3.8
6.9 ± 5.5
4.4 ± 3.8
Average Roof
Closed
6.9 ± 5.4
4.7 ± 4.0
5.1 ± 4.2
3.4 ± 3.0
s = seconds
21
CHAPTER FIVE
Discussion
5.1 Discussion
The study aimed to see the effects that both the gender of the athlete and the
court surface has on rally length in three of the professional Grand Slam tennis
Championships. Furthermore, to identify whether any differences exist between
rally length within a match and how it may vary between sets. Finally to see if the
newly implemented roof over centre court at Wimbledon affects the rally lengths
produced.
5.2 Rally Data
A key factor when analysing the length of each individual rally and the number of
shots it consists of, is the surface on which play has been undertaken. Girard and
Millet (2004) claimed that the characteristics of the ground surface influences the
technical and physical demands of that player and defines the player’s game
style. They further added that net rushers would prefer faster court surfaces that
would enable them to move forward to the net, where as aggressive baseliners
would appreciate a more slow court surface that results in longer rallies from
behind the baseline. Unieryski and Hurnik (2004) added further backing by
stating that fast courts help create a player with an aggressive, ‘all court’ game or
serve and volley game, whilst clay courts would encourage players to rally from
behind the baseline.
Consequently, clear differences across the court playing surfaces are seen from
the results of this study for both rally durations and number of shots per rally.
Significant differences (p ˂0.001) were found to exist for both rally durations and
number of shots per point across all court surfaces grass, clay and hard courts.
Unierzyski and Wieczoirek (2004) produced results that show differences
between the grass courts at Wimbledon and the clay courts of Roland Garros.
They found that 97% of all the rallies when played at Wimbledon ended within 5
shots, with only 3% ending between 6-9 shots. They did not find a rally on grass
that consisted of more than 10 shots. In comparison, they also found that 61% of
points at Roland Garros ended in a short rally (5 or less), 22% consisted of 6-9
22
shots and 17% had rallies lasting more than 9 shots. Furthermore, Hughes and
Clarke (1995) found that the average number of shots per point was 52% greater
at the Australian Open than at Wimbledon; however the average times of each
rally was 93% greater. The results indicating that not only did Wimbledon see
less shots per point but the shots
occurred more rapidly after one another.
These findings present solid evidence, alongside the results of this study, that
different playing surfaces present different playing conditions for the players.
Consequently, Wimbledon and Roland Garros are seen as extremely prestigious
events, not just because of the tradition around the event, but also due to their
specific demands for both tactical and technical skills that are necessary to
succeed on that given court (Unierzyski and Wieczoirek, 2004).
Furthermore, by looking at the past winners of each Grand Slam, and having
knowledge on the winners playing style, it is clear a difference between each
playing surface and the chosen tactics and playing styles exists. In the men’s
game, Roger Federer is widely regarded as the most successful player in the
history of the game winning 17 grand slam tournaments. Of these 17 grand slam
titles, seven were won on grass courts at Wimbledon, nine on the hard courts of
the Australian and US Open and only one on the clay courts of Roland Garros.
With Federer being known as an all-round player, with a strong serve and the
ability to both play from the baseline and approach the net (Top Tennis Training,
2013a), it can be seen as to why he has won across all of the surfaces. However,
with only one win on the clay courts compared to the seven on grass, differences
between the requirements to win each tournament are seen. Pete Sampras, 14
times Grand Slam champion, is another example of how being successful on
each playing surface requires differing tactics and playing styles. Sampras was
always seen as a player that adopted a serve and volley approach (Top Tennis
Training, 2013b) and by adopting this style it allowed him to win seven
Wimbledon titles across a span of eight years. Therefore reinforcing the notion
that Wimbledon and grass courts, suits players that adopt a serve and volley
approach, resulting in shorter, more rapid points being played. This being
represented in the results of this study with Wimbledon showing both the shortest
duration of rally and the least number of shots, a possible outcome of a strong
service and serve and volley tactics. In comparison, Sampras never won a
23
French Open title on the clay, suggesting that he did not have the ability to adopt
a baseline strategy that the clay courts require in order for a player to be
successful in the longer durations of rallies that this study found to be applicable
on clay courts. Leading to further application of the theory that each tournament
requires different tactical and technical approaches in order to be successful.
Within the women’s game similar results have been observed. By again looking
at the most contrasting tournaments, Wimbledon and the French Open, and their
winners, differences once again exist. The Williams sisters, Venus and Serena,
have been seen as the dominant players over the recent decade. Since 2000, of
the 13 Wimbledon championships that have been played, 10 of them have been
won by a Williams’s sister. Both Serena with a strong serve and powerful
groundstrokes and Venus with skillful volleys and strong net approach (Diffen, No
Date) are suited to the requirements of the grass game. However, by analysing
the past winners of the French Open for the same time period, it shows a
Williams’s sister has won only one of the last 13 French Open championships.
This could be due to many factors, such as their service being neutralised due to
the court surface, inability to consistently be successful in longer rallies that were
found to be present in this study, inefficient in their movement around the court or
being unable to maneuver their opponent in order to gain the upper hand in the
rally. As a result, this would further develop the premise that different
requirements exist to win on grass and clay for the women’s game too. It can be
clearly observed over recent history that strong servers and net rushers suit the
aspects of a grass court, with results for women’s rally lengths showing the
shortest rally durations and least number of shots for this study. However, by
choosing to implement this playing style and strategy, they will therefore struggle
to be successful on the clay courts that require a player to be more comfortable
on the baseline and effective in longer rallies, such as the results of this study
suggest, with women showing the longest rally duration on clay as well as the
most number of shots.
The influence of gender also has an effect on rally durations and shots per point,
as well as the playing surface. Previous literature has produced results that show
women tending to have longer rally durations than men (O’Donoghue and Liddle,
24
1998; O’Donoghue and Ingram, 2001). This was believed to be because of
women building up the rallies slower in order for them to determine and exploit
the opponent’s weaknesses (Gunter, 1973). However, the results of this study
contradict this as men produced longer rally durations at the French and US
Opens, as well as the most number of shots per point on all three of the playing
surfaces. This would suggest that the findings of both Furlong (1995) and
O’Donoghue and Brown (2008a) are not applicable to the results of this study.
They proposed that service was more important within the men’s game, resulting
in shorter rallies when compared against the women’s game, with men gaining an
advantage with the use of a good serve, a point further highlighted by
O’Donoghue and Ballantyne (2004) who produced figures on service advantage
in both the men’s and women’s game. They found that ladies gained the lowest
service advantage at the French Open (54%) with men gaining the highest at
Wimbledon (64%). But with the results showing men producing longer rally
durations than women, it would lead to the view of Davies (1962), who proposed
that the properties of the men’s and women’s game will eventually equalize, to be
true for rally lengths.
Further important aspects on rally length are to look at how it has developed and
changed over recent decades. Takahashi et al. (2009b) study produced results
on how rally lengths have changed from the 1980s to the 2000s. They found that
time durations as well as shots per point were longest in the 2000s, possibly due
to the decreased service winner that was observed. As a consequence, it was
proposed this change was due to players improving their service return, resulting
in a decrease of serve and volley approaches and therefore a longer duration of
points. The results of this study saw an increase for men in both shot durations
(Richers, 1995; Hughes and Clarke, 1995; O’Donoghue and Liddle, 1998;
O’Donoghue and Liddle, 2001; Takahashi et al., 2006) and the number of shots
per point (Hughes and Clarke, 1995; Unierzyski and Wieczorek, 2003; Verlinden
et al., 2004; Takahashi et al., 2006) in comparison to past findings.
This
development further emphasises the premise that rally length is increasing in the
modern day game, with less players adopting a net rush, serve volley approach
and more implementing an all-round game strategy. With these developments,
player’s mentality and physical approach to the game could potentially need
25
investigating. As games will elicit longer rallies, which would require the player to
be more efficient in maneuvering around the court and to be able to complete
such movements on a more regular occurrence over a longer, more sustained
period of time.
5.3 Set Data
By segregating each individual match into sets for analysis it therefore allows for
a greater detailed picture of how the game had developed throughout. Choi,
O’Donoghue and Hughes (2009) discovered that a distorted picture of relative
performance indicators can be attained through using whole match data and it is
clear that differences are seen in the results of this study when the match is
separated into sets, especially for the men’s game.
The opening games within the first set are critical for both players as they look to
settle down into the match and begin to read the opponent and the tactics that
they may have employed. Consequently, the player will continuously make
decisions about their position on court and therefore the tactical moves that they
employ in order to gain the upper hand (Verlinden et al., 2004). As a result, the
rallies that take place in the opening set may be longer than the average, as each
player is testing each other for weaknesses that they can target, strengths that
they must not allow the opponent to utilise or to develop an understanding of the
tactics that the opponent has put in place. Results of the men’s analysis would
apply to this theory as it was seen that a higher than average rally duration and
number of shots per point were seen in the first set, with a gradual decline taking
place within set two and three. Looking at the decline that was found, it is
possible that the men started to anticipate the opponent’s shots more effectively,
resulting in a shorter rally. Filipčič, Filipčič and Berendijas (2008) claimed that
contemporary development trends within tennis look to shorten each point played
and therefore the match in general. With the knowledge that higher skilled racket
sport players are more effective in picking up subtle information on an opponent’s
postural orientation prior to the ball or racket being swung (Williams, Davids and
Williams, 1999), it can be assumed that players will begin to anticipate the
26
opponent’s shots, resulting in them having the desired upper hand in the rally,
allowing them to dictate the points.
The obvious intention of tennis players is to win the match as quickly as possible,
within three sets for men and two sets for women, as this will allow the player to
have a physical advantage over possible opponents in the subsequent rounds
who has required more time on court (O’Donoghue, 2004). However, sometimes
this is not the case and results in a fifth set for men and third set for women being
played. The last set brings new problems for the players as physical and mental
fatigue, as well as nerves that have developed throughout the match, begin to
affect performance. It is also claimed that the margin for players between winning
and losing a 5-set tennis match is frequently small, with the match being played
over several hours differences in physiological performance between opponents
of similar technical and tactical ability may be crucial to success (Christmass,
2008). With this in mind, rally specific results of the last set show that men saw
the longest duration of rally and the most shots per rally in the fifth set and
women showing a below average duration and number of shots per rally in their
third set. With the results contrasting it is important to remember that only one
complete match was analysed for each gender and therefore the effects of the
final set for each gender are not fully understood.
The final set of any tennis match will inevitably lead to the players feeling
nervous, as both players are starting from an equal position with a deciding set
the difference between progressing through the championships and being
eliminated. Therefore, it is possible the players may adopt one of two
approaches. Firstly, players could adopt a strategy to shorten the points as both
physical and mental fatigue could begin to set in and negatively affect their
performance. Fatigue could cause the players to make bad decisions throughout
the rally, whether it is making a bad shot selection, going for a winner too early or
not being able to get in the right position prior to their shots. As a result, players
may therefore begin to rush to the net earlier in the points, or even adopt a serve
volley approach so that the effect of fatigue can be minimized and the points
shortened. Secondly, nerves could affect the player’s confidence and result in
them changing the way that they may have been playing. Attacking players may
27
adopt a more defensive, ‘just get the ball back’ approach and wait for the
opponent to make mistakes, possibly leading to longer rally durations.
Furthermore, players may have knowledge on the opponent regarding how they
cope physically and mentally in five set matches and play accordingly.
In terms of the findings of this study, men showed an increase in both rally
duration and number of shots in the last set. As stated above, this could be due
to nerves and the composure of the player under pressure or an implemented
strategy in order to beat their opponent. Knowing that only two of the fifteen
analysed matches contained a full five set match, the true effects of a fifth set and
the impact it has on rally lengths are not understood. However, with the
knowledge that one of the analysed five set matches was the US Open Final
between Andy Murray and Novak Djokovic, assumptions could be made. With
such pressure on the last set, a winner takes all situation, both rally durations and
number of shots increased from what was seen in set four. It could be assumed
that this was due to nerves of winning the championship and both players not
willing to risk attacking strategies that could result in a higher amount of unforced
errors and cheap points given to their opponent.
5.4 Impacting Factors of Extraneous Variables
The implementation of the roof over centre court at Wimbledon has initiated many
discussions. This study investigated the effects that the new roof had on both the
durations and the number of shots that each rally consisted of.
Firstly, it is important to distinguish how the roof works and the implications that it
therefore has on tennis performance. The roof was first and foremost
implemented so that play could be undertaken when rain would have otherwise
delayed play. The roof was designed so that it was able to maintain a pre-existing
level of light and air when it was open and then when it is required to be closed,
an air flow system helps remove condensation from within the bowl to provide a
court surface that enables the game of tennis to be played (Wimbledon, No
Date). However, problems have arisen over the effect that the roof has on the
28
development of play. Pete Irwin, Hawk-Eye expert at Wimbledon stated that “Due
to the increase in humidity when the roof is closed, balls are heavier and travel
slightly slower through the air” (Smith, 2011). Andy Murray also commented on
the roof after his 2012 first round victory over Daniel Gimeno-Traver that “The
roof changes the conditions and if anything it’s almost too perfect. It’s different
grass court tennis” (Smith, 2011). Furthermore, Hawkeye data has shown the ball
to be travelling up to 5 mph slower when it reaches the receiver if the roof is shut
(Haake, 2011). With all this in mind it is possible to suggest that with the roof
closed the court starts to play similar to that of a clay court. This could possibly
result in service becoming a less important factor and baseline rallies becoming a
more regular and integral factor when the roof is closed, resulting in longer rally
durations and more shots being played per point.
It is difficult to contribute to the on-going debate on the effect of the roof due to
the contradictory results of this study, with a longer duration and more shots per
rally for men being shown and a shorter duration and less shots per rally for
women. These results themselves have reliability issues due to the sample size
that was used with only one complete match for both men and women being
analysed. This further raises issues with generalising the results as not all playing
styles and tactics have been analysed. For example, the analysed woman’s
match was the Quarter Final match between Serena Williams and Petra Kvitova
and it is widely regarded that Serena Williams has the most effective serve within
the woman’s game. This would therefore skew the results of the study towards a
shorter duration of rally as her serve allows her to win more points with aces and
unreturned serves. Although only one match was analysed under the roof, three
matches containing Serena Williams were analysed. As a result, comparisons
can take place between Williams playing under an open and closed roof. The
comparison indicates that Williams produced the shortest durations and least
number of shots when playing under the roof when compared against the two
matches that she played when the roof was open, thus, in this instance,
disproving the notion that the roof slows down play producing longer rallies.
For a better detailed overview of the effect of the roof more matches would need
to be analysed, with all the playing styles (serve and volley, baseliners, all court)
29
needing to be analysed leading to a more detailed conclusion being given on the
effect of the roof.
30
CHAPTER SIX
Conclusion
6.1 Conclusion
In conclusion, the key results indicated that men have continued to have a
greater length of rally than women on clay and hard courts, however women saw
a longer rally duration when playing on the grass courts of Wimbledon, but fewer
shots were played. Significant results were found when comparing both rally
duration and number of shots across the three playing surfaces (p<0.01), with
clay showing the longest rally duration and grass the shortest. Interrogation of the
within match variables, identified that in the men’s game the rally duration as well
as number of shots decreases gradually from set 1 to set 3, with an increase
being seen in set 4 & 5. Women saw set 2 produce the longest rally data, with set
1 & 3 showing similar results.
The results of this study alongside previous literature could be used by players
and the team that supports them. Within such a team, a strength and conditioning
coach, physiologist and psychologist may exist alongside the main coach for that
player. Said people could use these findings to tailor the training regime and
approach into each championship and its specific requirements, in order for the
player to be in peak mental and physical fitness.
Further developing this topic, future research can look into how rally durations
and number of shots per point varies between the different playing styles that are
employed. Players could be split into groups that categorise their playing styles
(serve and volley, all court and baseliners), to observe if the implemented tactics
of both players within the match effect the duration of rallies. Detailed research
could also be undertaken to understand the true effect that the roof at Wimbledon
has on the game of tennis. Whether this is in terms of rally durations and shots
per point, or how the now virtual indoor grass court affects player’s service. This
research could provide essential information for players, coaches, committee
members of that given championship and the International Tennis Federation on
how the roof changes aspects within the game. This information becomes more
invaluable with the knowledge that Roland Garros plans to implement a roof over
centre
court
in
time
for
31
the
2016
championships.
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37
APPENDICES
Appendix A
List of analysed matches.
French Open
Men
Ferrer vs. Granollers (4th Round)
Djokovic vs. Seppi (4th Round)
Murray vs. Ferrer (Quarter Final)
Djokovic vs. Federer (Semi Final)
Djokovic vs. Nadal (Final)
Women
Zakopalova vs. Sharapova (4th Round)
Kuznetsova vs. Errani (4th Round)
Kanepi vs. Sharapova (Quarter Final)
Stosur vs. Errani (Semi Final)
Kvitova vs. Sharapova (Semi Final)
Wimbledon
Men
Ferrer vs. Del Potro (4th Round) (Played under roof)
Federer vs. Malisse (4th Round)
Djokovic vs. Mayer (Quarter Final)
Murray vs. Tsonga (Semi Final)
Federer vs. Murray (Final) (Played part of match under roof)
A-1
Women
S Williams vs. Shvedova (4th Round)
Radwanska vs. Kirilenko (Quarter Final) (Played part of match under roof)
S Williams vs. Kvitova (Quarter Final) (Played under roof)
Radwanska vs. Kerber (Semi Final)
S Williams vs. Radwanska (Final)
US Open
Men
Berdych vs. Almagro (4th Round)
Del Potro vs. Roddick (4th Round)
Djokovic vs. Del Potro (Quarter Final)
Murray vs. Berdych (Semi Final)
Murray vs. Djokovic (Final)
Women
Vinci vs. Radwanska (4th Round)
Ivanovic vs. Pironkova (4th Round)
Azarenka vs. Stosur (Quarter Final)
Azarenka vs. Sharapova (Semi Final)
S Williams vs. Azarenka (Final)
A-2
Appendix B
SPSS Outputs
Test Statisticsa
Rally_duration
No_of_shots
Mann-Whitney U
3862204.000
3851318.000
Wilcoxon W
6309782.000
6298896.000
-1.403
-1.590
.161
.112
Z
Asymp. Sig. (2-tailed)
a. Grouping Variable: gender
Test Statisticsa,b
Rally_duration
Chi-Square
No_of_shots
108.541
74.225
2
2
.000
.000
df
Asymp. Sig.
a. Kruskal Wallis Test
b. Grouping Variable: surface
Test Statisticsa
Test Statisticsa
N
Chi-Square
df
Asymp. Sig.
5782
3706.526
2
.000
N
5782
Chi-Square
7342.142
df
2
Asymp. Sig.
.000
a. Friedman Test
a. Friedman Test
B1