Voros Mc Cracken - DIPS

DIPS

McCracken first published his ideas about DIPS in 1999 on the rec.sports.baseball newsgroup on Usenet. He also effectively named the new concept of "defense independent pitching" with that publication: "I've been working on a pitching evaluation tool and thought I'd post it here to get some feedback. I call it 'Defensive Independent Pitching' and what it does is evaluate a pitcher base strictly on the statistics his defense has no ability to affect...". His findings implied that major league pitchers had little control over the outcome of balls put into play against them and specifically that the percentage of balls put into play against a particular pitcher that fell for hits did not correlate across seasons. This implied that elements beyond the pitcher's control, including defense, ballpark, weather and randomness, had significant effects upon his performance.

McCracken's "Pitchers and Defense: How Much Control Do Hurlers Have?" was published on the Baseball Prospectus website in 2001 and was picked up on by baseball researchers and ESPN baseball writer and analyst Rob Neyer. After explaining McCracken's findings, including reporting some of his own calculations from the previous years' pitching statistics and describing the aspects of DIPS that were most original, Neyer concluded: "And it seems to me that anyone who wants to project pitcher performance should read McCracken's article, because it'll blow your mind." In his book The Numbers Game, Alan Schwarz writes that McCracken told him “all hell broke loose” after Neyer's column appeared. McCracken received nearly 2,000 emails in the next couple of days and thousands more in the ensuing months.

Sabermetrician Craig Wright agreed that hit rate is not as heavily influenced by the pitcher as is commonly believed, but at the same time concluded "... some emphasize pitches that are tough to hit sharply enough to get your share of hits on balls in play. I don't think the latter is a primary way for pitchers to distinguish themselves from others, but I do believe it is a more significant factor for some groups than others." He specifically cited two groups, knuckleball pitchers and flyball pitchers, as examples of those who tend to allow fewer hits on balls in the field of play. Subsequent independent research by Phil Birnbaum, Clifford Blau and Tom Tippett confirmed Wright's findings, but Wright still praises McCracken as "... the guy who really got people to understand that most folks overestimate the pitcher's ability to influence the number of hits that result from balls batted into the field of play."

Bill James also expressed some skepticism but recognized the potential value of McCracken's findings if further research bore them out. He argued that "the research really should be done, for several reasons. First, if McCracken turns out to be correct, this has important consequences, even allowing us, to a certain extent, to predict movements in pitcher's records. . . ." In his New Historical Baseball Abstract in 2001, James acknowledged that McCracken was correct, that the results were significant, and that James himself felt "stupid for not having realized it 30 years ago." Rob Neyer also noted the impact of McCracken's discovery on James' subsequent work. McCracken's discovery and its influence on baseball analysis is outlined in Moneyball: The Art of Winning an Unfair Game by Michael Lewis.

McCracken continued to refine his new statistic, including addressing the issue of knuckleballers in his DIPS 2.0 in 2002. He published DIPS statistical results as well as extensions and improvements to his initial formulas in other forums, including Baseball Primer (now Baseball Think Factory).

Baseball researchers have continued to evaluate and to propose refinements to DIPS, such as Tom Tippett in his 2003 article "Can Pitchers Prevent Hits on Balls in Play?". McCracken also continued to think about how to measure performance in a variety of organized sports, including soccer.