Hillman's Bane, or, Estimating the Platoon Skills of Some Royals Hitters

Platooning: Something every semi-serious baseball fan, player, executive, and manager understands. Um, right?

No, this isn't another anti-Hillman rant. Rather, I knew that the silent millions who read yesterday's column at Driveilne Mechanics on platoon splits were demanding more, all the more eagerly for their silence. So here, using the same methodology from that article, are the estimated platoon skills of some of the hitters on the 2009 Royals.

I won't bore you with the methodology -- go to the original post for that (as well as Alex Gordon and Miguel Olivo's splits... seriously, go there for those). I've explained the headings below. Simply note that

• I didn't include switch hitters, since we have a pretty good idea of their splits after 600 PAs. Maybe I'll go back and include them later.
  
• I'm not projecting their hitting, I'm just giving a "best estimate" of their true platoon skill based on the evidence we have so far. Read the Driveline post, or, failing that, read about the reiiability scores below.
  
• I'm estimating the ratio  of the split, not the actual "amount" (which would require a full-blown projection of the players true hitting talent)  -- better hitters tend to have larger splits.
• Projections are only for OBP and wOBA.
• The key to the table follows... I'm willing to try to answer your questions, but, again, it might be worth reading the original post first.
• No, I did not forget Alex Gordon and Miguel Olivo...
• In 2008, the average RH OBP split was 6.1%, RH wOBA split was 5.0%. 2008 LH OBP split: 6.4%, LH wOBA%, 7.2%. This is pretty typical -- lefties have larger splits on average, and they vary more from player to player among lefties.

Table Key:

• PAvsis career plate apperances vs. LHP only.
•  OBPspl and wOBAspl are the career OBP/wOBA split of the player.
• OBP% and wOBA% are what the career split as a percentage.
• xOBP% and xWOBA% are the expected "true" split percentage.
• Rel. is a similar to a Marcels reliability score, in that it is based on the number of PAs vs. LHP the player has as a percentage of his total Pas vs. LHP + PAs of lgAvg. They should be taken as purely "relative" to one another in this context however, not as anything like a "percentage chance this projection is right." I don't know how helpful they are. The reliability scores of lefties and righties should only be compared to one another, as well, since 1) the are regressed a different amount, and 2) there is a greater variance of platoon skills amoung left-handed hitters than right-handed hitters. I thought about doubling all the right-handed Rel. scores, but I'll let people figure it out. I thought about leaving them off entirely; I hope they don't distract from the main point of the piece.

This is a deliberately crude methodology, and if more than half the guys end up closer to my "estimate" than their career split, I'll consider it a success, although that will neither prove nor disprove the principles it is based on, of course. I hope some people find this stuff interesting.

I'll forego my own commentary on individual players and let people fill in the blanks in discussion, if they would like. I'll simply say that if this study (based on, you guessed, something from The Book) is somewhat close to accurate, the Royals team split vs. RHP and LHP last year was and outlier -- they should be expected to be better against RHP and worse against LHPs, because most of their best (projected) hitters are left-handed, and they have (typically) larger splits. The only right-handed hitter consistently projected to be above average is Billy Butler (keep your fingers crossed!).