Joe Girardi catches a lot of grief for making handedness a big part of his in game strategy. I've been a part of that hate train before, but there are certainly numbers to indicate that many Yankees batsmen have been considerably better against opposite-handed pitching. There is an advantage to be gained through platoon splits. There is also the potential to burn through a bullpen and keep talented hitters on the bench. A happy medium is what any manager should be shooting for, but there will always be shades of gray in this kind of decision making.
Another thing regarding matchups: While I agree with the internet consensus that batter vs. pitcher data is fairly useless to apply directly -- meaning that if Batter A is seven for twenty in his career against Pitcher B, that is next to meaningless -- I think that another level of meaning falls directly out of platoon splits. Derek Jeter doesn't hit lefties better because of how they write with a pen, he hits them better because of how the pitch is presented to him. Some combination of being able to see the ball better, see the ball for longer, and the direction of the movement. From that, it stands to reason that different batters would be more successful against different types of pitchers. Handedness is one way to split pitchers into groups, but there are others -- power pitchers, finesse pitchers, sinker ballers, etc.
A manager using data to try to put his players up against opponents that they are likely to succeed against is commendable. I'll live with that approach, even if there is the occasional overzealous response to some small sample size numbers. It's part of the gig.
- In a somewhat similar vein, there was a flurry of numbers comparisons between Eric Chavez and Alex Rodriguez when A-Rod hit the DL. Their lines still look very similar. Rodriguez is at .278/.358/.460 while Chavez is at .282/.341/.480. What was often missed was that A-Rod had played every day while Chavez had had his playing time cherry picked to face only right handed pitchers. The thirty-six times that Chavez has been left in to face a lefty this season, he is batting .161/.222/.161. For his career, Chavez has a higher OPS by 150 points against righties. The Eric Chavez that plays every day does not get compared to Alex Rodriguez.
- Raul Ibanez is on this team to hit right handed pitching. Eric Chavez has been much better at doing that and can give A-Rod DH days. Ichiro Suzuki has done it about the same (.322 vs. 319 wOBA) and is a transcendentally better outfielder. There isn't a whole lot of reason for Raul Ibanez to be starting games.
- Last season, Robinson Cano had a .373 wOBA against left handed pitching and a .373 wOBA against right handed pitching. The season before, he had a .406 wOBA against right handed pitching and a .368 wOBA against left handed pitching. For his career, Cano had been a little bit better against righties, but never really neutralized by bringing in a lefty. We can all hope that it's statistical noise and an outlier season -- it very well could be -- but a .223/.281/.332 is somewhat worrisome.