MGL sent me the 2007-2008 PZR files and allowed me to share my win value calculations with you.  Using the same methodology as I used for the 2001-2006 win values, I calculated PZR-based WAR for 2007 and 2008.  Here are 2007-2008 win values, 2001-2008 win values ordered by name, 2001-2008 win values ordered by year, and 2001-2008 totals.  I'll also summarize the 2007 and 2008 leaderboards and provide an updated 2001-2008 leaderboard.

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It is well-established that pitchers have control over their ground ball and fly ball rates--some pitchers, like Roy Halladay, are known for their extreme ground ball tendencies.  But what allows these pitchers to achieve a markedly different batted ball profile from the average pitcher?  I decided to use Pitch f/x data to determine whether batted ball rates depend on pitch type (as classified by Gameday) and location.

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When we use a DIPS-based pitching statistic like FIP to calculate win values, our intention is to isolate the pitcher's contributions from those of his defense.  FIP, however, is only a crude approximation of the truth: it assumes that all pitchers should have a league-average BABIP, it fails to correct for double plays and pitchers who struggle out of the stretch, and as a linear run estimator, it underestimates good pitchers and overestimates bad pitchers.  PZR does a much better job of isolating pitching from defense without removing the effects of timing or hit quality.  PZR is UZR, but from a pitcher's perspective.  The pitcher is credited the run value of each batted ball, based on its trajectory, location, and speed, regardless of whether or not the ball fell for a hit.  When these run values are totaled, we obtain a measure of a pitcher's "defensive support;" we can estimate his true performance by adding his defensive support to his actual runs allowed.  As a result, PZR is perfect for Win Values, since it separates defense from pitching without removing anything else.

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Ever since Voros McCracken published his original article on DIPS in 1999, sabermetricians have been attempting to isolate pitching from fielding.  Tody the most widely used metrics are Tom Tango's FIP and Graham MacAree's tRA; FIP focuses solely on strikeouts, walks, and home runs allowed, while tRA also accounts for batted ball type.  Yet possibly the best defense-independent value metric is little-known PZR, or Pitcher Zone Rating.

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DIPS theory--the idea that a pitcher has little control over the outcome of balls in play--is possibly sabermetrics' most controversial idea.  Many fans maintain that a pitcher, by consistently locating in the right spots, can induce weak contact and thus lower his batting average on balls in play.  I took all balls in play (including home runs) from 2008, and using the gameday XML data, assigned them to one of 13 bins (I reversed the coordinate system for LHB's).  Bins 1-9 are all inside the strike zone, while Bins 10-13 are balls.

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