Range Factor (commonly abbreviated RF) is a
baseball statistic developed by
Bill James. It is calculated by dividing
putouts and
assists by the number of
innings or games played at a given defense
position.[1] The statistic is premised on the notion that the total number of outs in which a player participates is more relevant in evaluating that player's defensive play than the percentage of cleanly handled chances as calculated by the conventional statistic
fielding percentage.
However, some positions (especially
first baseman) may have substantially more putouts because of a superior infield around them that commits fewer
errors and turns many
double plays, allowing them to receive credit for more putouts. Also,
catchers who have many strikeout
pitchers on their team will have a high range factor, because the catcher gets the putout on a strikeout if the batter does not reach base.
All-time single-season leaders
Note:All-time single-season leaders are listed according to Range Factor by games played (A + PO) / G. Yearly leaders listed above from 2001–present are listed according to Range Factor per nine innings 9 *(A + PO)/ Inn. Because the latter statistic is unavailable for older players, the former figure is used below to ensure use of comparable data for the all time single season leaders. The figures set forth below are verified from
Baseball-Reference.com.