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Rajai Davis & 80 Steals: Part Two
Posted By R.J. Anderson On March 8, 2010 @ 8:00 pm In Daily Graphings | 12 Comments
Part one dissected the claim and found that Davis attempting enough steals to successfully swipe 80 was improbable due to a number of factors. In part two, let’s focus more on the analytical side. I’m going to shamelessly steal an idea from Jeff Sullivan, but first some disclaimers and notes.
This process is going to blanket all steals attempts as being in equal in leverage. This is obviously untrue and affects how baserunners would approach certain scenarios. Certainly Davis is going to be more focused in and less willing to risk a caught stealing in the ninth inning of a tied game instead of the third inning when the A’s are up by four. Context is important, but it’s just not something I can accurately adjust for here.
Let’s assume the league run environment is around 4.5. As Sullivan notes, that makes the run value of a stolen base roughly 0.19 runs and a caught stealing is worth approximately -0.45 runs. One failure is worth two-and-a-third successes in such an environment.
The above chart details the minimum amount of attempts needed at various success rates to reach 80 steals. The best case scenario is that Davis turns into one of the most efficient basestealers in league history and needs fewer than 100 steals to rack up 80. The worst? Davis is caught left and right, but still allowed more than the 120 attempts necessitated by his performance to reach 80. Let’s turn these numbers into run values.
The same overlay is in effect here. The colored cells represent the point in which Davis would have at least 80 steals. The green means positive, the red means negative; or, in other words, not worthwhile to give Davis the green light to such an excessive degree. To surmise both parts: Davis is highly unlikely to get 80, but barring a total decay of his stealing skills, he’d probably make it worth the A’s time by adding a few runs.
The real intriguing part of the chart is look at the contrast between high success rates with moderate attempts and moderate success rates and higher attempts. Stealing bases isn’t always about volume. Perhaps the real goal Henderson should set for Davis isn’t 80 steals, but an 80% success rate.
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