Intro Batting Stats
Abbreviations
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G = Games Played
PA = Plate Appearances
AB = At-bats
H = Hits
BB = Base on Balls
K = Strikeout
IBB = Intentional Walk
HP = Hit by Pitch
SH = Sacrifice Hits (Bunts)
● R = Runs Scored
● RBI = Runs Batted In
● 1B = Singles
● 2B = Doubles
● 3B = Triples
● HR = Home Runs
● SF = Sacrifice Flies
● TB = Total Bases =
1(1B) + 2(2B) + 3(3B) + 4(HR)
AVG/OBP/SLG - The Slash Line
● Batting Average (AVG) = H / AB
○ Popular, commonly used
● On-Base Percentage (OBP) =
(H + BB + HP) / (AB + BB + HP + SF)
○ The “Moneyball” stat
● Slugging Percentage (SLG) = TB / AB
○ Idea of player’s power
● Ex: Mike Trout 2014 - .287/.377/.561
Mike Trout 2013 - .323/.432/.557
OPS and ISO
● OPS = OBP + SLG, simple but useful
● Isolated Power (ISO) = SLG - AVG
● Ex: Mike Trout 2014 - ISO = .274
Mike Trout 2013 - ISO = .238
● All these metrics are useful in comparing
performance, but don’t provide full picture
● Want to understand why...
Discipline
● BB% = Walk Percentage
= BB / PA
● K% = Strikeout Percentage
= K / PA
● Provide context on batter’s
plate discipline
● For power hitters both tend
to be high
● Obviously prefer higher
BB%, lower K%
● K% has been on the rise
Batted Ball
● Batting Average on Balls In Play (BABIP)
○ BABIP = (H - HR) / (AB - K - HR + SF)
○ 3 main influences
■ Defense - Better fielders, hit into shifts
■ Luck - Bloop singles, at’em balls
■ Talent Level
○ Lets us determine if a batter’s slash line is sustainable or
not
○ Need to look at BABIP relative to player’s career
○ Roughly 800 balls in play to stabilize
○ If current BABIP deviates greatly….?
Batted Ball Cont.
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Better players tend to have higher BABIP
Harder the ball is hit, more likely it is a hit
Line Drive Percentage (LD%) = Line Drives / Balls in Play
Fly Ball Percentage (FB%) = Fly Balls / Balls in Play
Ground Ball Percentage (GB%) = Ground Balls / Balls in Play
Infield Fly Ball Percentage (IFFB%) = Infield Fly Balls / Fly Balls
Informs us of the type of hitter we are looking at
More line drives tends to result in higher BABIP due to true talent
More fly balls or ground balls with higher BABIP indicates luck
Roughly a year and a half for rates to stabilize
Limitations - “A ball isn’t a fly ball or a line drive, it is hit at X launch angle, Y
degrees from center, at Z velocity”
Comparison:
Mike Trout vs Bryce Harper
Comparison:
Mike Trout vs Bryce Harper
Intro Pitching Stats
Abbreviations and #KILLTHEWIN
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W = Wins
L = Losses
G = Games
GS = Games Started
CG = Complete Games
ShO = Complete Game
Shutout
● IP = Innings Pitched, .1
represents ⅓, .2 represents ⅔
● TBF = Total Batters Faced
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SV = Saves
HLD = Hold
BS = Blown Save
BB = Walks Allowed
SO = Strikeouts
H = Hits Allowed
R = Runs Allowed
IBB = Intentional Walks
HBP = Hit by Pitch
WP = Wild Pitches
Earned Run Average (ERA)
● ER = Earned Runs Allowed
● An earned run is a run scored without the aid of errors
by the field (i.e. by hits, walks, and outs that advance
runners)
● ERA = (ER * 9) / IP
● Average number of earned runs allowed thru 9 IP
● Very popular but with serious faults
● Relies too heavily on context
Walks plus Hits per Innings Pitched (WHIP)
● WHIP = (BB + H) / IP
● Measures average number of base runners
a pitcher allows per inning
● Associated a pitcher’s effectiveness however
it originated for fantasy baseball
● Along with ERA, does not include strikeouts
and heavily dependent on hits allowed...
Other Useful Metrics
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K / 9 = Average number of SO per 9 IP
BB / 9 = Average number of BB per 9 IP
K / BB = SO to BB ratio
K% = SO / TBF, frequency of SOs
BB% = BB / TBF, frequency of BBs
LOB% = Left On-Base %, percentage of
pitcher’s own base runners that they strand
● Also use the batted ball metrics LD%,....
Common Sense
● December 1999, baseball fan Voros
McCracken developed a new way of
measuring pitching
● Questioned whether or not a pitcher could
do anything about balls in play
● Concluded that what happens after a ball is
put in play depends on the defense
● Pitcher solely controls BB, SO, and HRs
Defensive Independent Pitching Stats
● So McCracken developed DIPS
● Fielding Independent Pitching (FIP)
○ FIP = (13HR + 3(BB+HBP) - 2K) / IP + constant
○ This constant brings FIP to an ERA scale
■ constant = lgERA – (13lgHR+3(lgBB+lgHBP)-2lgK) / lgIP
○ Strips away defense, more stable indicator of a
pitcher’s ability acting as an expected ERA
○ Essentially assumes average defense and luck
○ Values derived from run values (explore next week)
Understanding BABIP and FIP
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Pitchers have little control over their BABIP allowed
Using FIP and BABIP together we can assess whether or not
a pitcher is unlucky
Ex: Max Scherzer 2012, ERA = 3.74, BABIP = .333, FIP =
3.23
Max Scherzer 2013, ERA = 2.90, BABIP = .259, FIP =
2.74
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Over long periods of time will closely follow ERA but can vary
greatly in short run - Brandon McCarthy in 2014 (look him up
on Twitter)
Can help understand a team’s defense as well
xFIP - assumes a league average home run to fly ball rate
FIP and xFIP are just the first of many great pitching metrics
SIERA
● Skill-Interactive ERA
● Similar to FIP and xFIP however it does NOT ignore
balls in play
● This additional complexity is to attempt to more
accurately assess a pitcher’s skill
● Tells us more about the how and why of pitching
compared to other metrics
● Drawback is its complexity, different calculations for
sites
SIERA Cont.
● Similar scale with ERA just like FIP
● Park adjusted and includes a term for run environment
● Important factors it highlights:
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Strikeouts are better than FIP suggests - pitchers with more strikeouts have
lower BABIPs, have lower HR/FB ratio, and get more ground balls in double
play situations
Walks are bad, but worse for pitchers with higher walk rates
Relief pitchers have lower BABIPs and HR/FB
More baserunners a pitcher allows, the higher percentage of them will score
Balls in play are complicated - but more ground balls are easier for the
defense
Comparison: Kershaw vs Bumgarner
Next Week...
Runs Created and Linear Weights