Author's Formula for Measuring a Player's Defensive Ability Is Up for Debate
By Dave Sheinin
Washington Post Staff Writer
Sunday, May 14, 2006; Page E09
Any good baseball argument invokes the use of statistics, whether to compare the relative merits of two players or the worthiness of an aspiring Hall of Famer. But while 20-win or 30-home run seasons are clear benchmarks for pitchers or hitters, no such equivalent exists for defensive ability.
Are such skills measurable? Author John Dewan has come closer than anyone else to quantifying defense in his book "The Fielding Bible," but some skeptics suggest Dewan -- with an assist from noted stats guru Bill James, Dewan's business partner and friend -- has just tried to do something that can't be done.
Baseball Info Solutions, employs "video scouts" who review every major league game, charting every batted ball and recording its direction, location, speed, type (line drive, fly ball, etc.) and result. Given any combination of those factors, a computer can spit out how frequently such a play is made by the average major leaguer at that position.
"For example," Dewan said, "vector 17 extends from home plate to a spot between shortstop and third base. On a softly hit ball to that location, the average shortstop makes that play 26 percent of the time."
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