Baseball Defensive Metrics
Author: Baseball Bob
What’s the single best metric for assessing offensive performance in baseball? And how about for defensive?
Please don’t say OPS or OPS+.
There is a stat called AOPS (Adjusted On-base Plus Slugging)
Definition follows:On-base percentage and slugging averages are added and normalized for the context of the offensive level of the league and the player’s home park(s( and then converted to a scale in which 100 is average.
This normalized figure is given for every offensive player that ever appeared in a MLB game and is presented in the ESPN Encyclopedia of Baseball, Fifth Edition. Very interesting reading.
Example: Henry Aaron has a 150+ rating for his career. Which means that he is half again better than an average player. His highest season is listed at over 180+.
Ted Williams is scored at 186+ for his career. Damn good, eh?
Barry Bonds comes in at 182+, Lou Gehrig at 182+.
The Babe (Ruth) is all by himself at 209+. These are all career figures. Individual seasons are higher and lower.
Fielding is a whole “nother” ball game. Many sabermetricians are at work on comprehensive ratings of fielding prowess. One of the most promising is the plus/minus idea of John Dewan.
His firm is called Baseball Info Systems (BIS) An explanation of how it works is published in the John Dewan 2009 Fielding Bible. Available at Amazon Books.
There might be an example or explanation on line but I haven’t tried to find it.
Senate Session 2010-03-26 (11:38:58-12:56:02)