Splitting Range, Positioning, and
Throwing in Runs Saved
2016 SABR Analytics Conference
Scott Spratt
[email protected]
The Existing Range and
Positioning System
Formerly called the Plus/Minus System
Relies on batted ball location and velocity data
Credits or debits fielders relative to how often similar
plays had been made in recent seasons
The Existing Range and
Positioning System
Example: A ball is hit in the third base-shortstop hole
at 55 mph
Expected Out Rate = 60%
If Made = (1.0 – 0.6) = 0.4 plays of credit
If Unmade = (0.0 – 0.6) = -0.6 plays of credit
Advantages of the Existing System
Credit proportional to difficulty
Naturally centers
Easily translates to run values
Captures multiple facets of defense (e.g. range,
throwing)
Limitations We Wanted to Address in
this Research
Want to be able to know why a fielder is performing
well or poorly (e.g. range, throwing)
Credit/debit individuals on defensive shifts (e.g. Brett
Lawrie problem)
Splitting Range, Positioning, and
Throwing into Separate Components
You could model the existing Plus/Minus System like:
A
D
Where
A = Expected Out Ratio given the batted ball characteristics
D = Play is Made (1.0) or Play is Not Made (0.0)
Splitting Range, Positioning, and
Throwing into Separate Components
The new system will have two additional midpoints:
A
B
C
D
Where
A = Expected Out Ratio given the batted ball characteristics
B = Expected Out Ratio given the batted ball characteristics
and the initial positioning of the fielders
C = Expected Out Ratio once (if) the ball is fielded
D = Play is Made (1.0) or Play is Not Made (0.0)
Splitting Range, Positioning, and
Throwing into Separate Components
Here is how each component is calculated:
A
B
C
D
Positioning Plus/Minus = B – A
Range Plus/Minus = C – B
Throwing Plus/Minus = D – C
RPT Plus/Minus = D – A, analogous to existing Plus/Minus
Splitting Range, Positioning, and
Throwing into Separate Components
A
B
C
D
Splitting Range, Positioning, and
Throwing into Separate Components
Variables: A
Batted Ball Type (groundball
or air ball)
Batted Ball Velocity
Batted Ball Location
Batter Speed
Splitting Range, Positioning, and
Throwing into Separate Components
A
B
C
D
Splitting Range, Positioning, and
Throwing into Separate Components
2B
SS
Variables: B
Batted Ball Type (groundball
or air ball)
Batted Ball Velocity
Fielder/Batted Ball Distance
Batter Speed
3B
1B
Splitting Range, Positioning, and
Throwing into Separate Components
A
B
C
D
Splitting Range, Positioning, and
Throwing into Separate Components
Variables: C
Distance from Throw Base
Time to Throw
An Issue with Positioning Plus/Minus
2B
What if the Expected Out
Ratio for shortstops on this
play was 90% and the
Expected Out Ratio for
second basemen was
70%?
SS
3B
1B
Eliminating Over-Credits to
Positioning
To prevent this over-crediting of individual
positioning, we will instead calculate
Positioning Plus/Minus = Team B – Team A
Eliminating Over-Credits to
Positioning
Here is how each component is calculated:
A
B
C
Positioning Plus/Minus = Team B – Team A
Range Plus/Minus = C – B
Throwing Plus/Minus = D – C
RPT Plus/Minus = D – Team A
D
Results
Some simplifications in these results:
Looks at only groundballs
Applies a flat 0.75 run value for the hit/out
difference
Range, Positioning, and Throwing
Runs Saved - SS Leaders 2015
Fielder
Positioning
Range
Throwing
Total
Adeiny Hechavarria
-1
8
6
13
Brandon Crawford
-1
4
10
13
Francisco Lindor
4
6
3
13
Didi Gregorius
11
5
-4
12
Andrelton Simmons
-5
6
10
11
Range, Positioning, and Throwing
Runs Saved - 2B Leaders 2015
Fielder
Positioning
Range
Throwing
Total
Jose Altuve
6
-6
14
14
Ian Kinsler
0
7
3
10
Addison Russell
0
12
-3
9
Kolten Wong
0
9
-1
8
Logan Forsythe
7
2
-2
7
Range, Positioning, and Throwing
Runs Saved - 3B Leaders 2015
Fielder
Positioning
Range
Throwing
Total
Nolan Arenado
1
5
8
14
Manny Machado
-1
6
6
11
Jake Lamb
0
7
2
9
Tyler Saladino
3
2
4
9
Kyle Seager
-3
1
9
7
Range, Positioning, and Throwing
Runs Saved - 1B Leaders 2015
Fielder
Positioning
Range
Throwing
Total
Brandon Belt
0
2
7
9
Adrian Gonzalez
0
3
4
7
Mike Napoli
2
3
2
7
Lucas Duda
2
2
2
6
Paul Goldschmidt
1
1
4
6
Range, Positioning, and Throwing
Runs Saved - P Leaders 2015
Fielder
Positioning
Range
Throwing
Total
Dallas Keuchel
0
5
3
8
Jaime Garcia
0
5
2
7
Jake Arrieta
0
7
0
7
Zack Greinke
0
4
1
5
Gio Gonzalez
0
3
1
4
Range, Positioning, and Throwing
Runs Saved - C Leaders 2015
Fielder
Positioning
Range
Throwing
Total
Wilson Ramos
0
0
1
1
Tyler Flowers
0
0
1
1
Francisco Cervelli
0
1
0
1
Derek Norris
0
1
0
1
Caleb Joseph
0
1
0
1
Range, Positioning, and Throwing
Runs Saved - Team Leaders 2015
Team
Positioning
Range
Throwing
Total
Giants
1
14
19
34
Astros
0
5
21
26
Cubs
1
29
-5
25
Royals
-4
2
22
20
Indians
21
-4
2
19
Positioning in Shifts
Team Leaders/Trailers 2015
Team
Pos Runs Saved
Team
Shifts
Rays
15
Rays
1,465
Orioles
14
Astros
1,417
Rockies
11
Rockies
1,011
Yankees
9
Pirates
972
Indians
6
Yankees
929
Component Correlations
From 2013-15, Excludes Catchers
Component
Correlation
Positioning Runs Saved
.10
Range Runs Saved
.28
Throwing Runs Saved
.33
RT Runs Saved
.26
RPT Runs Saved
.27
Component Correlations
From 2013-15
Component
Total Shifts to Positioning
Runs Saved on Shifts
Correlation
.61
Acknowledgments
Ben Jedlovec and Joe Rosales
John Dewan
Everyone at Baseball Info Solutions