The Futility Infielder

A Baseball Journal by Jay Jaffe I'm a baseball fan living in New York City. In between long tirades about the New York Yankees and the national pastime in general, I'm a graphic designer.

Monday, February 03, 2003

 

DIPS and Data

With slow news days in the baseball world lately (the Yanks are spending money; an idiot ump is on the loose) and plenty of chaos at my j-o-b, I've been retreating to the serenity of my spreadsheets lately. It looks as though I'll be spending a bit more time there, as I've taken it upon myself to run all of the 2002 Major League pitching statistics through my DIPS 2.0 spreadsheet.

I don't take credit for the DIPS (Defense Independent Pitching Statistic) system. It was invented by a man named Voros McCracken, and he's presented DIPS numbers for the 1999-2001 seasons via his web site while explaining the system on Baseball Primer and Baseball Prospectus. The gist of it is that McCracken did some studies on pitching statistics involving balls in play and concluded that major-league pitchers do not differ greatly in their ability to prevent hits on those balls hit into play (that is, anything that's not a home run, a strikeout, a walk or a hit-by-pitch). The rate at which a pitcher allows hits on balls in play is due more to the defense playing behind him than to his own skill, and can vary greatly from year to year.

This is somewhat counterintuitive, but it's also a very helpful way of looking at pitching stats. DIPS takes the elements of a pitcher's record that are not affected by the defense -- walks, strikeouts, hit-by-pitches, homers -- and places them in a neutral context for park, league and defense. The result is a translated line of Defense Independent Pitching Statistics, including a DIPS ERA; that is, an ERA based on defense-independent pitching performance. An important thing about this DIPS ERA, McCracken found, is that it correlates better with the following season's ERA than the pitcher's actual ERA does.

For one reason or another, Voros decided not to publish DIPS numbers this year, leaving a sizeable void in the sabermetric universe. But he's already published fairly coherent instructions on how to calculate DIPS (and he encouragingly answered questions about some of the less coherent aspects of it), so I built a spreadsheet that would do the job. I used it for a few pieces about the Yankee pitchers and this year's crop of relievers figuring the sheet would give me a jump in the analysis department, but that it was only a matter of time before somebody published complete DIPS for 2002, and more power to them.

Insert sound of crickets chirping.

Nobody's done so, including myself -- mainly because I was never able to get my hands on the raw data in a spreadsheet. But via a rather mundane Primer thread, I managed to find somebody ("mathteamcoach" is his handle) who had most of what I needed. We've joined forces to share the tedium of entering Intentional Base on Balls and Batters Faced Pitching data for EVERY SINGLE PITCHER in the service of this project. It's a dirty job but somebody's got to do it, and between the two of us we're about 2/3 done. The results should be finished later this week.

Comments: Post a Comment

Subscribe to Post Comments [Atom]





<< Home

Archives

June 2001   July 2001   August 2001   September 2001   October 2001   November 2001   December 2001   January 2002   February 2002   March 2002   April 2002   May 2002   June 2002   July 2002   August 2002   September 2002   October 2002   November 2002   December 2002   January 2003   February 2003   March 2003   April 2003   May 2003   June 2003   July 2003   August 2003   September 2003   October 2003   November 2003   December 2003   January 2004   February 2004   March 2004   April 2004   May 2004   June 2004   July 2004   August 2004   September 2004   October 2004   November 2004   December 2004   January 2005   February 2005   March 2005   April 2005   May 2005   June 2005   July 2005   August 2005   September 2005   October 2005   November 2005   December 2005   January 2006   February 2006   March 2006   April 2006   May 2006   June 2006   July 2006   August 2006   September 2006   October 2006   November 2006   December 2006   January 2007   February 2007   March 2007   April 2007   May 2007   June 2007   July 2007   August 2007   September 2007   October 2007   November 2007   December 2007   January 2008   February 2008   March 2008   April 2008   May 2008   June 2008   July 2008   August 2008   September 2008   October 2008   November 2008   December 2008   January 2009   February 2009   March 2009   April 2009   May 2009   June 2009   July 2009   August 2009   September 2009   October 2009   November 2009   December 2009   January 2010   February 2010   March 2010   April 2010   May 2010  

This page is powered by Blogger. Isn't yours?

Subscribe to Posts [Atom]