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In baseball, defense-independent pitching statistics (DIPS) measure a pitcher's effectiveness based only on statistics that do not involve fielders (except the catcher). These include home runs allowed, strikeouts, hit batters, walks, and, more recently, fly ball percentage, ground ball percentage, and (to much a lesser extent) line drive percentage. By focusing on these statistics, which the pitcher has almost total control over, and ignoring what happens once a ball is put in play, which the pitcher has little control over, DIPS can offer a clearer picture of the pitcher's true ability. Originally, the most controversial part of DIPS was the idea that pitchers have little influence over what happens to balls that are put into play. But this has since been well established (see below), primarily by showing the large variability of most pitchers' BABIP from year to year. In fact, the outcome of balls in play is dictated largely by the quality and/or arrangement of the defense behind the pitcher, and by a good deal of luck. For example, an outfielder may make an exceptionally strong diving catch to prevent a hit, or a base runner may beat a play to a base on a ball thrown from a fielder with sub-par arm strength. ==Origin of DIPS== In 1999, Voros McCracken became the first to detail and publicize these effects to the baseball research community when he wrote on rec.sport.baseball, "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. . ." .〔http://groups.google.com/group/rec.sport.baseball.analysis/msg/b450fe58c05a5a82?hl=en&lr=〕 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.〔Voros McCracken, "Pitching and Defense: How Much Control Do Hurlers Have?," (BaseballProspectus.com, January 23, 2001 ).〕 McCracken reasoned that if this ability existed, it would be noticeable in a pitcher's 'Batting Average on Balls In Play' (BABIP). His research found the opposite to be true: that while a pitcher's ability to cause strikeouts or prevent home runs remained somewhat constant from season to season, his ability to prevent hits on balls in play did not. To better evaluate pitchers in light of his theory, McCracken developed "Defense-Independent ERA" (dERA), the most well-known defense-independent pitching statistic. McCracken's formula for dERA is very complicated, with a number of steps.〔(Defense Independent Pitching Stats Part II )〕 DIPS ERA is not as useful for knuckleballers and other "trick" pitchers, a factor that McCracken mentioned a few days after his original announcement of his research findings in 1999, in a posting on the rec.sport.baseball.analysis Usenet site on November 23, 1999, when he wrote: "Also to () is that, anecdotally, I believe pitchers with trick deliveries (e.g. Knuckleballers) might post consistently lower $H numbers than other pitchers. I looked at Tim Wakefield's career and that seems to bear out slightly".〔http://groups.google.com/group/rec.sport.baseball.analysis/browse_thread/thread/f9f708f94ccb8696/b450fe58c05a5a82?lnk=st&q=+voros+%EE%8A%B7nse-independent-pitching-stats#b450fe58c05a5a82〕 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.〔http://www.baseballthinkfactory.org/files/newsstand/discussion/vorosmccracken_me_being_arrogant_again/P100/ in item 188〕 In 2002 McCracken created and published version 2.0 of dERA, which incorporates the ability of knuckleballers and other types of pitchers to affect the number of hits allowed on balls hit in the field of play (BHFP).〔(BBTF's Primate Studies Discussion :: DIPS Version 2.0 )〕〔(Defense Independent Pitching Stats, Version 2.0 Formula )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Defense independent pitching statistics」の詳細全文を読む スポンサード リンク
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