The Jackalopes prided themselves on being amazing hecklers. We dedicated a great deal of time to preserving a dying art. The penalties for a bad heckle were severe — buying a bucket of twenty beers and intense disparaging from one’s peers. However, we always left the umpires alone because we felt there was little point nailing neutral stewards of the game. However, if I knew then what I know now, things would have been much different.
Gamblers have always felt that umpires have a significant influence on the outcome of the game, but baseball’s statistical community was slow to research the umpires’ influence on the game. However, that has changed in recent years. Baseball Prospectus has been charting umpire tendencies for quite some time. Others have began delving into this, including Patrick Kilgo, who presented a study using Pitch f/x data at SABR 41. According to Kilgo’s study, umpires, on average, have an 84% accuracy rate in calling balls and strikes.
Andrew Goldblatt recently published, Major League Umpires’ Performance, 2007-2010, in which he charts R/9, K/9, BB/9, an K/BB for all umpires in that time period then compares them to the MLB average. Golblatt’s book is fascinating, not just because of the data he presents, but because he includes wonderful narratives for each umpire.
Goldblatt’s data indicates that there wide ranges in umpire results. For instance, in 2007, Mark Wegner led major league umpires with a 15.46 K/9 while Randy Marsh had the lowest K/9 with an 11.69 — almost a five strikeout per game difference (the league average was 13.34). In Runs/9 in 2007, Gerry Davis led the league with 11.81 while Jeff Nelson was 5.82 (LAVE 9.63). Goldbaltt doesn’t appear to make any adjustments the pitchers those umpires called for the season, so there obviously is noise in that data. It is important to remember that research is a process. Too many statheads want to discard research because the author isn’t using the the “best” technique. To paraphrase Chris Dial at SABR 41 in the hotel lobby, “Pardon me for being snarky, but you are free to conduct your own study. Until then, just STFU and listen.” Goldbaltt’s data is a wonderful starting point for others to start there own research, which I fully intend to do in a series of comparisons with umpire game logs from Retrosheet.