Keith sez,

Mays, Aaron, Dick Allen, Piazza all had about 100 pt OPS differences.

McCovey and Boog Powell were about 140 pts.  Thome was 300 pts.  Junior was 90 pts.  Reggie Jackson was about 100 pts.

Edgar was only 55 pts and Billy Williams had a 100 pt reverse split.

I picked them all at random and haven't left anybody out.  That was the entire list of historic guys I looked up.  Surely some people run nearly zero split difference.  Edgar wasn't at zero...but had a reduced platoon advantage.  Billy Williams was just weird.  A mashing, RH hitting Aoki.

But if some of the best hitters ever (and a bunch of those guys are in the Hall) show split differences why should anybody think it isn't "real?"  If you're going to say that 100 pts appears to be the normal split difference that is fine....but some guys clearly aren't normal.  Lind hits LHP at a career .589 rate.  Brendan Ryan hit lefties at a whopping .636 number (he was 40 pts worse against RHP).  When you run Lind out to 1B vs. lefties, you're essentially putting Brendan Ryan there, sans all the glovey things he did.

Now why wouldn't you platoon in such a situation, given a partner for Lind (260 pt split difference)?  Lind has 1000+ PA's vs. LHP.  He hasn't been "unlucky" vs. them.  He's just not very good.

For some people the split difference is negligible.  For some it doesn't make much difference. Hey, Willie Mays laid waste to RHP's, too. The Giants didn't carry a 4th OF who hit RHP better than Willie.  But for many MLB players there is a real difference, one that counts.  All things being equal, if you can platoon them to good effect then do it.

It's harder to do it with a Seager (108 pts better vs RHP...but still at .711 vs. LHP) because he brings a glove premium, regardless of the handedness of the pitcher.

A Lind doesn't really do that.  Nor does a Seth Smith (230 pt difference). 

Every team carries a 4th OF...if they give you a split advantage you SHOULD use them.  Few teams, for example, carry  (specifically) a 2nd 3B (although the Mets in '69 largely used a 3B Platoon: 1B, too).

Differences exist...and some guys have them that are beyond the norm.  It just is.

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Bill has always tended to make his points very emphatically in order to cut through the resistance, and get a broader point across.  In this case the broader, and good, point is that "The scouts' constant obsession with platoon splits --- > leave them in a place that is behind where they would be if they ignored splits."  This has been one of the big reasons that his 1975-2016 work has resonated.

Working with the Red Sox, James deals with a constant fire hose of scouting reports that say "Don't promote this guy.  He'll never hit lefties.  Or if you do, he'll only help you part time."

But when you run into a situation where Jim Thome had a 300 point split over the 50 years he played :- ) they still call that too little data.  Which puts them in a place where no particular group of hitters will dissuade them.  They forget, a little bit, to ask "If we were wrong, how would we know?"  In this case I can't imagine what argument would soften them up.  Keith is especially interested in platoon splits, and I am not sure where to go with them, so I hope he keeps it coming 100 MPH.

When it came to McCracken's theory on BABIP, Bill responded by saying "that's mostly true, but notice that Nolan Ryan allowed 100 fewer hits than expected over his career" ... when Baseball Prospectus said "there is no evidence that CERA varies by catcher," Bill's response was "That means we can't measure it.  I programmed a simulation where catchers DID have 1.00 ERA differences and your study still showed that CERA does not exist."  BJOL did an article on Big Game Pitching and found a bunch of guys were tremendous in the biggest 50 games in their careers - IIRC, Randy Johnson was in the top 5.  In terms of pitching better than his own norm.

Not to take anything away from James' analysis, but my own suspicion is that they are now understating the exceptions to the rule.

Platoon splits and clutch hitting (and, earlier, BABIP) they get a little too adamant about.  Pitcher BABIP and some other things, their attitude has been a little different.  As a chessplayer, I'm open to generalizations while keeping an eye for exceptions -- exceptions that apply to more than 1 player in 1,000.

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In any case, James is in favor of platooning because the GENERAL platoon advantage is worth building strategies around.  I would follow that on by platooning Adam Lind quicker than the average bear.  :- )  It could be that his "gusto" for finding 400-foot shots hurts him against LHP's ... he doesn't dial it back enough when the pitch angle limits his vision.  Contrast Robinson Cano, who is the same hitter LH-on-LH (AVG, OBP etc) except that his SLG goes down.  He dials it back.

Would be interesting Mo' Dawg on your expectation for 'Bach's future platoon splits.

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At SSI I hope we'll take Adam Lind, 'Bach, Aoki and other players on a case-by-case basis, while being alert to the idea that USUALLY the platoon splits are MOSTLY limited to TTO variation.

Great stuff Keith.

BABVA,

Jeff