August 17, 2006


Lies, Damned Lies: The Origins of the Closer (Nate Silver, 8/16/06, Baseball Prospectus)

Before we proceed, let’s concoct a quick-and-dirty way to evaluate a closer’s effectiveness. We can define a Closer Efficiency Index (CEI) as…

CEI = RA+ x (Saves x 2 – SvOpp) x (162 / TeamG)

…where RA+ is a pitcher’s run average relative to his league and park average, and TeamG is the number of games that the pitcher’s team plays during the regular season (this term is intended to put pitchers from strike-shortened seasons on equal footing).

CEI is not intended to replace something like WXRL, which is a far more informative metric, but it should do well for our purposes. John Smoltz in 2004, had an RA+ of 1.66 (his RA was 66% better than league average), and 44 saves in 49 opportunities; this produces a CEI of 64.8. This is an outstanding score--anything over 50 might be considered a great season, while anything over 100 is a Hall of Fame type season. The highest CEI’s of all time are as follows:

Jose Mesa 1995 183.7
Dennis Eckersley 1990 178.3
Eric Gagne 2003 171.1
Rollie Fingers 1981 163.5
Mike Jackson 1998 155.9

Jon Papelbon is within striking distance of this group; his CEI is 165 as of this writing.

Posted by Orrin Judd at August 17, 2006 2:35 PM
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