Mike Moustakas: One-Game Threat

With the World Series shifting to San Francisco for Game 3, the Royals have made some changes to their lineup. They’re not starting anybody as the designated hitter, because that would be against the rules. Ned Yost has elected to start Jarrod Dyson over Nori Aoki, which seems like the right thing to do. And Mike Moustakas has been bumped up to the fifth spot, with Alex Gordon soaring to second. It’s about as good a lineup as the Royals could have, under the circumstances, although there are two lefties back-to-back.

I’m not going to sit here and give you a prediction. However, there is one thing that might very slightly change the odds. You’ve seen broadcasts talk about x-factors before? Normally, they’re meaningless. Hell, maybe this one’s meaningless. But for this game, for this particular game, Moustakas should be one of the Royals’ best hitters. However small an advantage that presents, Moustakas has a couple of platoon factors working to his benefit.

I understand that, this year, Moustakas was one of the worst hitters in baseball. I understand that, this month, Moustakas has been one of the best hitters in baseball. Neither means all that much to me. Some things that mean more: Moustakas has a career .293 wOBA, Steamer now projects him for a .317 wOBA, and he’s left-handed.

The Giants are starting the right-handed Tim Hudson. So one of Moustakas’ platoon advantages is obvious. His career numbers reflect pretty normal splits — he’s been dreadful against lefties, and just below-average against righties. Now, using some math, we can manipulate those splits to get something of a current and more accurate projection. If you evaluate Moustakas by his career numbers, then right now you’d see him as about a .300 wOBA hitter against righties. But let’s say you believe in Steamer. Moustakas is young, and maybe improving. He just posted a godawful BABIP that might’ve masked some progress. Based on the Steamer projection, then right now you’d see Moustakas as about a .325 wOBA hitter against righties. That’s a good deal better. Let’s just compromise, then, and say the answer is somewhere in between .300 – .325. I don’t know where it is, exactly.

Of the two platoon advantages, that’s the one everyone knows about. The other one comes straight from The Book. To review, we’re talking about Mike Moustakas vs. Tim Hudson, for something like two or three plate appearances. Hudson’s well-known as a sinker-baller, meaning he’s well-known for generating a lot of grounders. Something that’s less well-known, but no less true, is that Moustakas frequently puts the ball in the air. For all of Moustakas’ faults, he hasn’t made a habit of grounding out.

Setting a minimum of 200 innings over the past three years, Hudson ranks easily in the top 10% of pitchers in groundball rate. Now let’s set a minimum of 500 plate appearances over the past three years. Moustakas ranks easily in the bottom 10% of hitters in groundball rate, and he ranks in the top 5% of hitters in fly-ball rate. So, statements confirmed: Hudson is a groundballer, and Moustakas is a fly-baller.

And that’s Moustakas’ other advantage. The A’s have built a lineup of fly-ball hitters, to work against the trend of more pitchers pitching down in the zone. Moustakas has the same principle working in his favor. As demonstrated in The Book, against a groundball pitcher, a fly-ball hitter has an advantage over a groundball hitter. Similarly, against a fly-ball pitcher, fly-ball hitters are comparatively worse off. The math of it is a little less straightforward, and I’m not going to bother, but we can say this: no matter where you put Moustakas’ expected numbers against an average righty, against a groundballing righty you bump the numbers up.

If it’s an explanation you want, it might have something to do with the swing plane. It could be that hitters with air-ball swings are better able to counter a pitch’s insistence on staying on the ground. Looking at Baseball Savant, over his career Moustakas has slugged .539 against pitches in the lower third of the zone. He’s slugged .470 against pitches in the middle third, and .378 against pitches at the top. If you prefer Brooks Baseball data, Moustakas in his career has hit .290 against right-handed sinkers, slugging .505 with a decent BABIP. One of Moustakas’ biggest problems as a major leaguer has been popping the ball up. A lot of the time that happens against four-seamers up in the zone. Sinkers aren’t commonly pop-up pitches.

Now Hudson, of course, doesn’t just throw sinkers to lefties 100% of the time. He’ll mix in a handful of other pitches, and I don’t know how he’ll pitch Moustakas, specifically. But just based on what we know about the splits, Moustakas has that pair of advantages. He has a lower career groundball rate against righties than he does against lefties, to boot. This is about as good a position as Moustakas can find himself in, aside from the fact that San Francisco’ ballpark is extremely pitcher-friendly.

Moustakas still doesn’t project as well as Alex Gordon, who’s only a little more neutral in terms of batted-ball distribution. But Eric Hosmer is a groundball hitter, working to offset his handedness platoon advantage. And Jarrod Dyson is an extreme groundball hitter, just like Nori Aoki, so that’ll be a factor for him. For the first several innings of Friday’s Game 3, it seems to me that Mike Moustakas is the Royals’ second-best hitter. He’s at least very close to Hosmer, and while this goes away in large part when Hudson is removed, everything matters. So often, Moustakas has looked helpless at the plate. Maybe he’ll look helpless again today. But it’s not often Moustakas has two different factors working in his favor. Consider this career data, from Baseball-Reference:

vs. FB pitchers: .629 OPS
vs. neutral pitchers: .633 OPS
vs. GB pitchers: .823 OPS

The odds are always against the hitters. The odds are always against Mike Moustakas. Tonight, they’ll be less against him than usual. At least for a handful of innings.