Identifying an accurate metric
for football efficiency
Tim Chou
Football Coach
Introduction: What’s the problem?
• Defense industry
– Stuck doing business the same way we did in the 80’s
• Coaching football
– Running the same drills we’ve done for 50 years
• Moneyball
– Thinking they can out-scout/out-coach everyone else
“That’s just the way we’ve always done things…”
Current (old) Football Metrics
• Defense
–
–
–
–
Total yards & points on defense
Yards per play
3rd down conversion %
Turnovers
• Offense
–
–
–
–
–
Total yards & points on offense
Yards per play
3rd down conversion %
Quarterback Rating
Time of possession
• Special Teams
– Touchdowns scored
– Yards gained
Are these the right metrics? NO!
Correlations using old metrics
YPG O vs Win%
YPG D vs Win%
120%
120%
100%
80%
YPG
100%
R² = 0.2647
80%
60%
60%
40%
40%
20%
20%
0%
0%
0
100
200
300
400
500
600
700
R² = 0.2466
0
100
PPG O vs Win%
120%
PPG
300
400
500
600
PPG D vs Win%
R² = 0.5046
100%
200
120%
100%
80%
80%
60%
60%
40%
40%
20%
20%
0%
R² = 0.4873
0%
0
10
20
30
Offense
40
50
60
0
10
20
Defense
30
40
50
What is the correct metric?
• Can one determine objectively, using
numbers, how “good” a team is?
– Identify a new way of accurately measuring how
good a football team is.
• How do we measure how good a special teams unit is?
The answer is measuring EFFICIENCY
Efficiency and Metrics
• Efficiency
– Describes the extent to which time, effort or cost is well
used for the intended task or purpose.
– Typically it measures the capability of a specific application
of effort to produce a specific outcome effectively.
• Metrics
– Performance metrics, a measure of an organization's
activities and performance. Operational metrics are used
in manufacturing and distribution to measure efficiency
and effectiveness.
– an analytical measurement intended to quantify the state
of a system.
The NEW measure of efficiency
• Measure an offense by how many yards they
need to gain to earn one point
• Measure a defense by how many yards they
force an offense to gain to earn one point
Total Yards (offense) / Total Points (offense)
Total Yards (defense) / Total Points (defense)
=
=
Yards per point (offense)
Yards per point (defense)
Yards per point (defense) – Yards per point (offense) = Yards per point differential
How many yards do you need to earn to gain one point?
Examining Yards per point
18
Yppoint differential
distribution
Yards per point differential vs Win%
16
100%
14
12
75%
10
R² = 0.771
8
50%
6
4
25%
2
0%
0
-9 -6 -4 -2 0 2 4 6 8 12
-10 -8 -6 -4 -2 0
2
4
6
8 10 12 14
Yards per point
Based on 2012 NCAA Division 1 college football stats (120 teams)
2012 CFB Yards per point differential
TEAM
Alabama
Notre Dame
Florida
Kansas State
Stanford
Georgia
Oregon
South Carolina
Texas A&M
Oregon State
YPP O
Rank
7
91
27
1
45
18
2
10
20
51
YPP D
Rank
2
1
4
18
8
11
21
15
22
16
Diff
Rank
2
1
3
5
12
11
10
13
17
21
DIFF w/ SOS
15.52
14.47
13.07
10.40
10.21
10.17
10.16
9.47
8.86
8.53
BCS AP
Win% Rank rank
92%
2
2
100%
1
1
92%
3
4
92%
5
7
85%
6
8
85%
7
6
92%
4
5
83%
10
11
83%
9
10
75%
13
15
Note: win% is NOT part of the calculation
Based on 2012 NCAA Division 1 college football stats (120 teams) as of the end of the regular season
2011 CFB Yards per point differential
YPP O
TEAM
Rank
LSU
1
Alabama
18
Oklahoma State
6
Wisconsin
3
Arkansas
11
Stanford
7
Temple
24
Oregon
8
Cincinnati
10
Kansas State
2
YPP D
Rank
1
3
13
15
28
27
2
31
7
65
Diff
Rank
1
3
8
4
15
12
2
13
5
19
DIFF w/ SOS
22.42
16.90
9.39
9.35
8.43
8.38
7.97
7.29
7.19
7.03
BCS AP
Win% Rank rank
93%
1
1
92%
2
2
92%
3
3
79%
10
9
85%
6
7
85%
4
4
69%
86%
5
6
77%
77%
8
11
Note: win% is NOT part of the calculation
Based on 2012 NCAA Division 1 college football stats (120 teams) as of the end of the regular season
Future applications
• Impacts coaching schemes, game preparation,
play calling, and even game time decisions
– Identify the target YPP differential (>5)
– Set targets YPP on offense (<13) and defense (>18)
• Allows for a different perspective on player
management: one step closer to “Moneyball”
– Manage risk and performance similar to an
investment portfolio
• Changes to calculations for betting lines
Takeaways
• We can use the data to draw some
conclusions…
– Efficiency appears to be a much better measure of
how good a football team is
– Coaches can use this metric to change their
philosophy on offense, defense, and special teams
– GM’s can use this metric as a foundation for
making player decisions
Questions?
Backup
Top Offenses (unweighted)
TEAM
Kansas State
Oregon
Louisiana Tech
Kent State
UCF
Ohio State
Alabama
San Diego State
Florida State
South Carolina
YPG O
410.4
550.1
577.9
391.2
400.7
423.8
439.1
407.8
465.9
372.4
PPG O
40.7
50.8
51.5
34.6
35.2
37.2
38.5
35.1
39.9
31.4
O YPPoint
RANK
1
2
3
4
5
6
7
8
9
10
O YPPoint
10.09
10.82
11.22
11.30
11.37
11.40
11.42
11.62
11.67
11.85
Does not account for strength of schedule
Based on 2012 NCAA Division 1 college football stats (120 teams) as of the end of the regular season
Top Defenses (unweighted)
TEAM
Notre Dame
Alabama
Rutgers
Florida
Cincinnati
Utah State
Boise State
Stanford
Iowa State
Northern Illinois
YPG D
286.83
246
321.25
283.42
373.75
322.67
304.67
338.92
444.83
356.69
PPG D
10.33
10.69
14.25
12.92
17.17
15.42
14.92
17.46
23.33
19
D YPPoint
RANK
1
2
3
4
5
6
7
8
9
10
D YPPoint
27.76
23.01
22.54
21.94
21.77
20.93
20.42
19.41
19.06
18.77
Does not account for strength of schedule
Based on 2012 NCAA Division 1 college football stats (120 teams) as of the end of the regular season
Yards per point differential vs Win%
100%
90%
80%
70%
60%
R² = 0.771
50%
40%
30%
20%
10%
0%
-10.00
-5.00
0.00
5.00
10.00
15.00
Case Studies
• Arkansas high school
– Never punt
– Always onside kick
• Oregon/Auburn’s hurry up no huddle offense
– Time of possession is NOT a significant factor to
winning or losing
• Other unorthodox methods?
NFL playoffs (cont.)
• Conference Championship
– New England (5.75) beats Denver (2.86)
– Seattle (6.38) beats Green Bay (2.75)
• Superbowl
– Seattle (6.38) beats New England (5.75)
Let’s put it to the test… NFL playoffs
• Wildcard Weekend
–
–
–
–
Baltimore (2.15) beat Indianapolis (-0.77)
Packers (2.75) beat Minnesota (1.88)
Seattle (6.38) beat Washington(1.51)
Houston (1.32) beat Cincinnati (2.37)
• Divisional Playoffs
–
–
–
–
Denver (2.86) beat Baltimore (2.15)
New England (5.75) beat Houston (1.32)
Green Bay (2.75) beat San Francisco (2.67)
Seattle (6.38) beat Atlanta (5.47)