Each of the following formulae uses innings pitched (IP), a measure of the number of outs a team made while a pitcher was in the game.
While the creators of DICE, FIP and similar statistics all suggest they are "defense independent", others have pointed out that their formulas involve (IP).
[2] A simple formula, known as Defense-Independent Component ERA (DICE),[3] was created by Clay Dreslough in 1998: In that equation, "HR" is home runs, "BB" is walks, "HBP" is hit batters, "K" is strikeouts, and "IP" is innings pitched.
[7] Dave Studeman of The Hardball Times derived Expected Fielding Independent Pitching (xFIP), a regressed version of FIP.
I call it 'Defensive Independent Pitching' and what it does is evaluate a pitcher base[d] strictly on the statistics his defense has no ability to affect..."[10] Until the publication of a more widely read article in 2001, however, on Baseball Prospectus, most of the baseball research community believed that individual pitchers had an inherent ability to prevent hits on balls in play.
[13] In later postings on the rec.sport.baseball site during 1999 and 2000 (prior to the publication of his widely read article on BaseballProspectus.com in 2001), McCracken also discussed other pitcher characteristics that might influence BABIP.
Like McCracken, Tippett found that pitchers' BABIP was more volatile on an annual basis than the rates at which they gave up home runs or walks.
However, improvements to DIP that look at more nuanced defense-independent stats than strikeouts, home runs, and walks (such as groundball rate), have been able to account for many of the BABIP differences that Tippet identified without reintroducing the noise from defense variability.
[18] Despite other criticisms, the work by McCracken on DIP is regarded by many in the sabermetric community as the most important piece of baseball research in many years.
For many people in the game and others who simply watch it, our ability to recognize the influence of defense, park effects, and dumb luck can be traced back to that one little article".