1 DOES THE BILL JAMES FORMULA FOR LEADOFF MEN STILL WORK? Bob Sawyer (
[email protected]) Bill James proposed a formula for evaluating leadoff men in the 1984 Baseball Abstract,. The basis of the formula was the probability of scoring given how far the leadoff man had advanced by his own efforts. For each time a leadoff man hits a home run he scores one run. For each 10 triples hit, James posited that a leadoff man would normally score 8 runs.(end note 1) For each 100 times they hit a double he posited leadoff men to score 55 runs. For each 100 singles, walks, and hit by pitch when no stolen base was attempted, James posited an expectation for 35 runs. For each time 10 bases stolen by leadoff men, he posited that 2 extra runs are scored, as this is the difference in expectation between a single and a double. Expected runs by a leadoff man was posited to reduce by 35 runs for each 100 Caught Stealing. Collectively, these postulates about expected scoring create a formula for estimating how many runs a leadoff man will score: Expected Leadoff RUNS = HR +0.8 x 3B + 0.55 x (2B + SB) + .35 x ( singles + BB + HBP – CS-SB) “Many players, and most modern leadoff men, will actually score about the number of runs that the formula says they should score. “ (p 684 The New Bill James Historical Baseball Abstract . Free press, 2001) In order for the formula to work, James postulates need to be good approximations for the actual scoring percentages.