Defensive Efficiency Record
From SABR Encyclopedia
(Difference between revisions)
Revision as of 01:51, 14 December 2009
Defensive Efficiency Record (DER) is a baseball statistic invented by Bill James to estimate the percentage of balls put in play by the opposition that a team's defense turned into outs. DER was privately published by James in 1980[1] and first publicly published in 1982 [2]. Like Fielding Percentage, DER is shown with three decimal places.
Formula
The process is to take the average of two estimates of plays made (PM) and divide by the estimated total of balls put in play.
PM1 = PO − K − DP − CA − OFA
where CA is total assists for team's catchers
and OFA is total assists for team's outfielders.