Who are the best defensive
center fielders?

Updated: June 11, 2002, 6:20 AM ET
By by Craig A. Rolling, STATS. Inc.
The ability to play first-rate center-field defense might be one of the most under-appreciated skills in baseball. Positioning, getting a good jump on the ball and quickly covering a lot of ground often can make the difference between a flyout and a two-run double. Sure, you might say, but how do we measure such things?

While fielding metrics are still less common and less straightforward than batting stats, we now have ways of analyzing defense that go beyond errors and highlight reels. For the purposes of this essay, we will rate the best defensive center fielders from 1999 through 2001 based on three statistics: Range Factor, Zone Rating and the brand-new Win Shares system developed by noted baseball author Bill James. We'll compare all the outfielders who logged at least 1,500 innings in center during these three years (there are 32 of them). Because the Win Shares system aggregates performance in left, center and right field, we will do the same with the other two metrics to be consistent.

Range Factor is perhaps the best-known of these three statistics, and also is the most straightforward to calculate. It's simply (((Putouts + Assists) * 9) / Defensive Innings). Since outfielders collect many more putouts than assists, a comparison of center fielders' Range Factors basically will tell us who caught the most balls relative to their time spent in the outfield.