Lycanthropy in Professional Baseball: Some Preliminary Findings

Although it is generally accepted that werewolves make up a certain percentage of major league baseball rosters, the stigma attached to the condition has made data collection difficult, and the anecdotal evidence has thus far been unsupported by empirical study. Here we take a first step towards a new, quantitative understanding of the prevalence of lycanthropy in baseball. Taking as our study population all MLB players above the qualifying threshold for playing time during the 2012 season, we measured their performance during full moon periods (FMP), i.e. periods from three days before to three days after a full moon. Metrics used were weighted on-base average (wOBA) for hitters, and fielding-independent pitching (FIP) for pitchers. A large number of players met our preliminary standards for lycanthropy, with statistically significant positive deviations in performance during full moon periods. Below are listed the five strongest candidates among both hitters and pitchers:

HITTERS (FMP wOBA – full-season wOBA)
Austin Jackson +0.072
A.J. Ellis +0.066
Adam LaRoche +0.063
Garrett Jones +0.062
Zack Cozart +0.060

PITCHERS (FMP FIP – full-season FIP)
Ubaldo Jimenez -1.46
Jason Vargas -1.15
Scott Diamond -0.98
Jon Lester -0.92
A.J. Burnett -0.89

To report some concrete instances of the phenomenon noted here: a full moon occurred on the night of July 3/4, 2012. That night, Austin Jackson hit a two-run home run, while Jon Lester, pitching in Oakland, put up the following numbers: 6.2 IP, 1 R, 4 H, 1 BB, 9 K. The following night, Jackson went 3 for 3 with a triple and a walk. The next new moon came on the night of July 18/19. Jackson went 0 for 4 with two strikeouts that night, after going 0 for 3 with a strikeout the previous night. Meanwhile, on Lester’s next start following the new moon — on July 22, pitching at home against Toronto — he put up these numbers: 4 IP, 11 R, 9 H, 5 BB, 2 K. Although these facts alone would not confirm a correlation, in light of the larger patterns identified above, they must be seen as strongly suggestive. This subject certainly deserves further study, and as it is the author’s belief that werewolves will soon be systematically outed in baseball, it is recommended that MLB take this opportunity to solidify its official positions on lycanthropy.