Justin Masterson picked up his first victory of the season last night despite a ground ball rate of 35.7%, his third lowest rate in the past two seasons. Despite being an extreme ground ball pitcher, pitching a game where his rate was in the mid-30's is not anything to be concerned about, given the small sample size. His good performance despite the aforementioned fact was an indication that the improved outfield defense kept the game under control more than they would have done so in the past.
Last season, when the outfield defense was arguably at its worst, Masterson had only three games with a GB% under 40: 6-15 vs. Pit, 6-26 vs. New York and 8-30 vs. Oak. The only game he won out of those three was against Pittsburgh, when he struck out nine.Last night, he only needed five strikeouts to get the victory. With more balls in play this time around, he still recorded the victory despite striking out fewer batters.
With a career ground ball rate of 56% mainly the product of the mid-90's sinker he throws, last night could be an indication that his career rate might slide a little south of that this season. If he continues to struggle with the command of his sinker, he might be more comfortable challenging hitters with his fastball because, in the back of his mind, he knows the outfield has a better chance of running the ball down if he makes a mistake up in the strike-zone than in years past.