Mike Napoli homered off Jon Lester Friday afternoon to help the Rangers to a 9-5 win over Boston in the season opener for both teams. In the last three season, Mike, a right-handed batter, owns a large platoon difference, hitting .304 against southpaws and .239 when the pitcher holds the platoon advantage. Graphically, it looks like this:
What accounts for the difference. The answer may lie in how pitches tend to move from the various pitchers. Right-handed batters tend to throw pitches that move away from Napoli:
Lefties, on the other hand, throw pitches that tend to move toward Mike:
So what kind of movement does Mike see when he gets a hit versus making an out?
Mike is much more likely to get a hit on a pitch that's moving in than a pitch that's moving away. Since lefties then to throw toward Mike, it's not surprising he hits them better. Where does Lester put the ball?
It was a perfect matchup for Napoli.