Scoring Probabilities

The following table shows scoring probabilities for various onbase situations. Each inning was evaluated by counting the number of instances of runners on first with no outs, one out, and two outs, runner on second with no outs, one out, etc.  If the runner scored in that situation it got counted as a score and divided by total instances of that occurrance.  The result is a percentage that could be used as  probabilities for betting purposes or other mathematics.

This table shows that a runner on first with no outs has a 33.4% chance of scoring.  A runner on second with 1 out has a 38.5% chance of scoring.  Thus, a manager who bunts a batter on first to second increases  probability of scoring by 5% but it costs an out.  A batter who steals from first to second increases scoring probability from 33.4% to 57.3%, a significant increase and doesn’t cost an out.

The data used to derive this table was taken from the 2013 set of events.  It is quite possible there may be a bug in my script used to do this counting.  To make this table more accurate I should pull data from one or more decades of events.

The baseline of scoring with no one on base and no outs is 28%.

Base_Out % Score Total Innings
1_0 0.334 3684 11015 46874
1_1 0.260 3131 12053 46874
1_2 0.121 1322 10889 46874
2_0 0.573 3073 5360 46874
2_1 0.385 3206 8327 46874
2_2 0.205 1853 9019 46874
3_0 0.827 1723 2083 46874
3_1 0.646 3238 5014 46874
3_2 0.260 1560 5998 46874