Stolen Base Percentage and Stolen Base Runs Calculator

In baseball, stealing bases tends not to help a team as much as getting caught stealing hurts. Sabermetric experts estimate that a player must successfully steal 2 bases for every instance of getting caught in order to break even; in other words, players need to succeed in base stealing attempts at least 67% of the time. On average, a stolen base only adds 0.3 runs to the game, so its overall value is much less that what intuition might suggest.

There are two metrics to measure the effectiveness of stolen bases. One is a player's stolen base percentage, abbreviated SB%, the other is stolen base runs, abbreviated SBR.

Stolen Base Percentage Formula

Stolen base percentage is a player's success rate in stealing bases, computed by dividing SB by the total number of attempts:

SB% = SB/(SB + CS),

If a player's %SB is above 0.667, then his contribution to the team is positive, otherwise his base stealing activity is actually hurting the team.

Stolen Base Runs

Stole base runs is the number of team runs created through stolen bases. The formula is

SBR = 0.3*SB - 0.6*CS

Whenever the number of stolen bases is twice the number of caught stealing, the SBR will be zero, the breaking even point. So long as SB is more than twice CS, this figure will be positive.

Example

In one season a player stole 21 bases and was caught stealing 9 times. His %SB and SBR are

SB% = 21/(21 + 9) = 0.7

SBR = 0.3(21) - 0.6(9) = 0.9

This player's success rate is 70%, but the total number of runs that he added to the game via stealing was less than 1.

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