Component 1: Stolen Bases, Caught Stealing, Pickoffs, Balks
In the first step of calculating Player Wins and Losses, baserunners, pitchers, and catchers are given credit and blame for either advancing (allowing) or failing to advance by (preventing) stolen bases (or defensive indifference) and for being caught stealing or picked off and failing to be caught stealing or picked off.1. Calculation of Component 1 Player Game PointsCredits for actual stolen bases, caught stealings, and the like are calculated simply as the change in Win Probability resulting from the change in the base/out situation (and the score, if appropriate).
Outs | Baserunners | SB | CS | Success Rate |
---|---|---|---|---|
0 | 1 | 5.3% | 3.1% | 62.8% |
0 | 2 | 1.2% | 0.5% | 68.6% |
0 | 3 | 0.2% | 0.1% | 57.4% |
0 | 1-2 | 1.5% | 1.3% | 52.4% |
0 | 1-3 | 4.0% | 1.1% | 78.2% |
0 | 2-3 | 0.2% | 0.1% | 61.4% |
0 | 1-2-3 | 0.2% | 0.1% | 60.3% |
1 | 1 | 5.8% | 3.7% | 61.0% |
1 | 2 | 1.9% | 0.9% | 68.2% |
1 | 3 | 0.3% | 0.6% | 30.9% |
1 | 1-2 | 1.8% | 1.4% | 56.9% |
1 | 1-3 | 4.7% | 1.8% | 71.8% |
1 | 2-3 | 0.2% | 0.3% | 39.4% |
1 | 1-2-3 | 0.2% | 0.3% | 45.6% |
2 | 1 | 6.7% | 3.7% | 64.4% |
2 | 2 | 1.0% | 0.3% | 79.0% |
2 | 3 | 0.4% | 0.2% | 59.9% |
2 | 1-2 | 1.0% | 0.5% | 66.1% |
2 | 1-3 | 7.1% | 2.0% | 77.9% |
2 | 2-3 | 0.3% | 0.2% | 66.6% |
2 | 1-2-3 | 0.3% | 0.2% | 62.4% |
WinProb = Prob(SB)•WinProbSB + (1-Prob(SB)) •WinProbnoSB
where Prob(SB) is the probability of a stolen base, which, as noted above, is base-out dependent. If no stolen base occurs, then the resulting Win Probability will be WinProbnoSB above, which can be calculated as follows:WinProbnoSB = [1/(1-Prob(SB))]•(WinProb – Prob(SB)•WinProbSB)
The net effect on Win Probability, then, of not stealing a base will simply be the difference: WinProbnoSB – WinProb.2. Division of Component 1 Game Points Between Pitchers and CatchersAs explained elsewhere, Component 1 Player Games are divided between pitchers and catchers based on the extent to which player winning percentages persist across different sample periods.
(Component 1 Win Pct)Even = b•(Component 1 Win Pct)Odd + (1-b)•(WinPct)Baseline
where (WinPct)Baseline represents a baseline winning percentage toward which Component 1 winning percentages regress over time.Persistence of Component 1 Winning Percentage: Baserunner on First Base
Pitchers: n = 40,981, R2 = 0.0000
WinPctEven = (25.38%)*WinPctOdd + (74.62%)*0.5000 (53.61)
Catchers: n = 8,624, R2 = 0.0000
WinPctEven = (22.63%)*WinPctOdd + (77.37%)*0.5000 (21.45)
Persistence of Component 1 Winning Percentage: Baserunner on Second Base
Pitchers: n = 40,412, R2 = 0.0000
WinPctEven = (12.03%)*WinPctOdd + (87.97%)*0.5000 (23.95)
Catchers: n = 8,523, R2 = 0.0000
WinPctEven = (3.68%)*WinPctOdd + (96.32%)*0.5000 (3.459)
Persistence of Component 1 Winning Percentage: Baserunner on Third Base
Pitchers: n = 38,632, R2 = 0.0000
WinPctEven = (-7.30%)*WinPctOdd + (107.30%)*0.5000 (-13.07)
Catchers: n = 8,307, R2 = 0.0000
WinPctEven = (19.27%)*WinPctOdd + (80.73%)*0.5000 (12.63)
3. Level of Credit for Not Attempting Stolen BasesPlayer Decisions are awarded not only for stolen bases and caught stealing, but also for a lack of stolen bases and caught stealings when given the opportunity. For most of the seasons for which I have calculated Player won-lost records, the failure to attempt a stolen base was actually a net positive for a base runner. That is, the expected gain in win percentage to an offensive team from a stolen base times the number of actual stolen bases (defensive indifferences and balks) was less than the expected loss in win percentage to an offensive team from being caught stealing times the number of actual caught stealings (including pickoffs). This has not been true every season, and, in fact, this tendency has reversed itself for seasons since 2007.
4. Baserunners versus Pitchers versus CatchersOverall, Component 1 Player Decisions account for 2.3% of total Player Decisions. The relative importance of basestealing as a component of total player value is quite different, however, for baserunners, pitchers, and catchers.