Edward Mujica: A case of gopheritis

Edward Mujica, right-handed pitcher for the San Diego Padres, is a pretty good middle reliever. Check out his numbers since coming to the Padres: Year Innings ERA K/9 BB/9 FIP xFIP tRA 2009 93.7 3.94 7.3 1.8 4.03 3.93 3.61 2010 31 3.19 9.3 1.2 4.79 3.10 3.94 The strikeouts and walks look good. There is one thing I purposely left out, however, and that is home runs allowed. Mujica has given up 22 home runs in 124.7 innings as a San Diego reliever. That is a 1.6 HR/9 rate. He will have trouble staying in the majors if he continues to allow home runs at this pace. Of course, perhaps he has just been unlucky or in a slump. We now have a variety of tools at our disposal to investigate Mujica’s home run troubles. First, let’s look at his ball-in-play rates (note that 2006-2008 with Cleveland is a pretty small sample, about 70 innings total): Year Line Drive Ground Ball Fly Ball IFFB HR/FB 2006 18.5% 26.2% 55.4% 19.4% 2.8% 2007 16% 26% 58% 17.2% 10.3% 2008 23.4% 30.5% 46...