With baseball slugger Barry Bonds again among the leaders in batting average and home runs, a lot of managers are falling back on the common strategy of walking the San Francisco Giants outfielder.
This strategy seems sound when facing the man who is on track to break the career home run record before he retires. But a Duke University statistician has run the numbers, and he says that in most cases the managers are wrong.
"I examined the number of runs scored by the Giants after each one of Bonds' plate appearances in 2001 through 2003," said Jerry Reiter, assistant professor of the practice at the Institute of Statistics and Decision Sciences at Duke. "When Bonds walks with the bases empty and no outs -- roughly 80 plate appearances over the three years -- the Giants score at least one run 46 percent of the time and average about 0.9 runs per inning. When he hits in these situations -- roughly 300 at-bats over the three years -- the Giants score at least one run 36 percent of the time and average about 0.6 runs per inning.
"These differences suggest that avoiding Bonds' home run power is outweighed by beginning an inning with a free pass. Pitching to Bonds is more effective than walking him in this situation."
Reiter analyzed other batting situations, and found that "with at least one runner on base, pitching to Bonds still seems to be the better strategy no matter how many outs there are."
It's only when there is no one on base and at least one out that the situation changes. "Here, statistics show that walking Bonds is more effective than pitching to him. The risk that Bonds hits a home run now appears to outweigh the risk that he scores when put on first base," said Reiter, who wrote an article on the subject in the January 2004 issue of the "Baseball Research Journal," published by the Society for American Baseball Research.
Reiter said these statistics were controlled for other factors, such as the quality of the pitcher and the player batting after Bonds.
So the next time Bonds starts an inning with a walk, Giants' fans shouldn't boo the opposing manager. He's actually doing their team a favor.