BOSTON -- Hit 'em where they ain't is ancient advice to baseball batters. Now statistics explain why it works.
Based on his time with the Texas Rangers, Alex Rodriguez is one of the game's best shortstops, according to researchers led by Shane T. Jensen of the University of Pennsylvania. Rodriguez now plays third base for the New York Yankees.
Using a complex statistical method, researchers concluded that one of the worst at shortstop is A-Rod's teammate, three-time Gold Glove winner Derek Jeter. The findings were presented Saturday at the annual meeting of the American Association for the Advancement of Science.
That method involved looking at every ball put in play in major league baseball from 2002 through 2005 and recorded where the shots went. Researchers then developed a probability model for the average fielder in each position and compared that with the performance of individual players to see who was better or worse than average.
Comparing Jeter and A-Rod, Jensen said, "suggests the Yankees have one of the best defensive shortstops playing out of position in deference to one of the worst defensive shortstops." A-Rod won two Gold Gloves as a shortstop before he came New York in 2004.
The worst? Bobby Higginson, formerly of the Detroit Tigers; ex-Yankee Bernie Williams; and Wily Mo Pena, now with the Washington Nationals.
Success depended on a player's range as well as good decision-making and positioning themselves well, said Jensen, an assistant professor of statistics at Penn's Wharton School.
Jensen said balls put into play fell into two categories:
• Grounders made up 42 percent. Fielding them required a player to move either left or right.
• Flies (33 percent) and liners (25 percent) make a fielder move left or right and either forward or backward.
Jensen said he expected fielders to do better running toward a fly to catch it. He was surprised that it turned out they were more successful moving backward. But it helped them that the ball was in the air longer.
Edward Aboufadel of Grand Valley State University in Allendale, Mich., said studies showed that outfielders try to run into a position where the ball appears to go straight up and straight down.