2011 Marlins Season Preview: Hitter platoon splits

My sincere apologies for missing out on a Thursday article, but the Maniac was held up all day in class and other school-related business. To make up for it, I have a double-shot of platoon-related goodness set up for the fellow Marlin Maniacs today, first in the form of projected platoon splits for the Marlins in the 2011 season.

The following are the projected wOBA splits against lefties and righties for Marlins hitters in 2011. These numbers are based off career platoon splits regressed appropriately to the three-year averages for league-wide splits as described in The Book. I used their projected wOBA based on ZiPS projections and figured out the wOBA splits from there. If you want to see more about how these platoon splits are derived, I described the process in greater detail in last season’s platoon splits piece. Keep in mind when reading these numbers that the approximate league average wOBA for a given season is around .330, which is just about the league average OBP for a given season. wOBA follows the same scale as OBP, so what you would think is a good OBP would be a good wOBA and vice versa.

Here are some thoughts and explanations on these numbers.

– The Marlins have three players in Ramirez, Coghlan, and Infante who have shown pretty even platoon splits over the course of their career. It actually isn’t surprising to me; I have a feeling that hitters who hit an abnormally high number of singles end up with decreased platoon splits compared to the average. However, because of the differing career lengths between those three players, they exhibit different projected splits. Remember, for hitters, platoon splits take longer to stabilize; for a right-handed hitter, we would need to see 2000 PA against lefties in order to suggest a split between the league average platoon split and a player’s career split. Lefties have it easier at 1000 PA versus left-handers, but the point still stands.

Coghlan is a good example. So far in his career, his split has been pretty even; he’s hit .298/.375/.400 versus lefties, good for a .348 wOBA, while against righties he has hit .303/.367/.441, good for a .354 wOBA mark. However, Coghlan has only faced lefties in 253 PA, only a quarter of that 1000 PA mark required to get a 50 percent split in true talent projected platoon split. As a result, we have to regress Coghlan’s numbers pretty strongly, which is why he is projected to hit a meager .327 wOBA versus left handers. Of course, that is still around the league average, so it certainly is nothing at which to scoff, but we should not simply treat Coghlan as bereft of any true talent platoon split.

Ramirez and Infante, on the other hand, have faced far more lefties in their career. Infante has faced just over 900 PA worth of lefty pitching, while Ramirez has faced 827. However, the benchmark for a right-handed hitter is much higher than that of a lefty, and as a result these guys are almost halfway to the 50 percent split mark of 2000 PA. We would weigh their splits at just about 20 percent and weigh the league average closer to 80 percent as a result. So while you still see a pretty significant split, it is still lower than that of Coghlan’s.

– I only included players with at least one year of major league play this season, so the only Marlins starter I ended up excluding is likely third baseman Matt Dominguez. In either lineup, I would expect Dominguez to bat eighth, so it does not really hurt to have his potential splits excluded.

– Last season Morrison showed a massive reverse split in terms of his platoon, hitting significantly better versus lefties (.414 wOBA) than righties (.351 wOBA). However, as John Herold pointed out on this blog once before, Morrison has actually shown a heavy platoon split in the expected direction; Herold projected him at a .308 wOBA versus lefties and a .386 wOBA versus righties based on his career numbers (by the way, Herold projected Morrison at a .367 wOBA in his second season, and Morrison managed a .368 wOBA in 2010. John Herold is really good at prospect projection). In these instances, it is good to point out that just because we saw one season’s worth of splits in an odd direction does not mean we would expect to see that going forward. As you can see, a properly regressed projection shows Morrison as better than the average lefty in terms of platoon splits, but not by much.

Later this afternoon, I’ll post the Marlins’ optimized lineups based on these platoon splits, as done by the guidelines shown in The Book. Stay tuned, the lineups should be very interesting.