Kansas City Royals v Chicago White Sox

A timeline:

  • May 22nd: Eno Sarris interviews the Royals about ideal ground ball and fly ball rates for hitters.
  • May 30th: George Brett takes over as the Royals hitting coach amid rumors that the team was too ground-ball heavy.
  • Since June 1: Extreme ground-baller Eric Hosmer has hit .311/.348/.517 with 10 homers while extreme fly-baller Mike Moustakas has hit .265/.317/.413 with 5 homers. Both have seen their ground- and fly-ball mixes even out.

So you’re welcome. (Gonna gloss over the fact that George Brett stepped down just the other day.)

Facetiousness aside, these two players have made me think differently about ground balls and fly balls. Talking to Josh Donaldson also crystallized it: players make decisions to alter their swing planes. For whatever reason, their swing planes are a place they look for change when they are struggling.

Seen against the backdrop of the fact that ground ball rates are among the quickest to stabilize, we’re stuck in a bit of a conundrum. If we can believe ground ball rates quickly, but players look to change them when struggling, and therefore change their ground ball rates… can we really believe in ground-ball rates so quickly?

I am not the man to answer that question.

What I can do, however, is investigate some recent changes in ground ball rates. This might tell us who might be gaining power (fewer ground balls) and who might be looking at a better batting average (more ground balls). Maybe we can’t look at the yearly ground-ball rates if the player might have made a change in that regard a month ago.

Four months are done. Ground ball rates stabilize in just over a month. For simplicity’s sake, let’s see who changed their rates dramatically since June 1. I have a hunch at least one Royal will be on this list.

First, the top 15 ground ball surgers.

Name GBMM-GBJJ PA BA HR R RBI SB
Carl Crawford -18.16% 271 0.284 5 40 16 10
Cliff Pennington -14.74% 242 0.247 1 22 17 2
Desmond Jennings -13.79% 453 0.261 11 68 40 16
Mitch Moreland -12.07% 342 0.241 14 36 40  0
Andrelton Simmons -10.30% 453 0.249 11 54 40 5
Alexei Ramirez -10.24% 442 0.279 1 42 26 23
Evan Gattis -10.18% 236 0.251 15 30 42  0
David Murphy -9.81% 369 0.223 11 36 33 1
Jean Segura -9.13% 443 0.317 12 60 42 31
Neil Walker -9.06% 325 0.242 6 35 30 1
Michael Cuddyer -8.74% 366 0.331 17 53 62 7
Nick Hundley -8.71% 259 0.245 8 24 27  0
Vernon Wells -8.35% 358 0.236 10 36 38 4
Victor Martinez -8.25% 438 0.270 9 45 59  0
Alejandro De Aza -8.14% 445 0.278 12 59 44 12

For some of these guys — Carl Crawford, Andrelton Simmons, Alexei Ramirez and even Alejandro De Aza in particular — this seems like a good move. They aren’t known for their power, and more ground balls could help boost their batting averages. It’s not working for Crawford, yet, but Simmons, De Aza, and Ramirez have all seen their bating averages go up. It may not be great news for Mitch Moreland and Evan Gattis on the other hand. It might be hurting their power output.

Now the guys that are hitting fewer ground balls.

Name GBMM-GBJJ PA BA HR R RBI SB
Michael Brantley 19.05% 406 0.279 7 50 51 11
A.J. Pollock 17.45% 320 0.251 6 43 29 6
Lorenzo Cain 17.38% 352 0.259 4 43 38 12
Josh Rutledge 17.26% 251 0.211 6 35 16 8
Chris Young 16.71% 263 0.191 9 33 30 7
Ben Revere 14.63% 336 0.305 37 17 22
Matt Kemp 14.08% 251 0.263 5 30 27 9
Domonic Brown 12.23% 402 0.271 24 51 69 8
Starling Marte 11.79% 459 0.277 10 66 30 30
Alcides Escobar 11.50% 426 0.238 3 39 34 12
Adrian Beltre 11.28% 451 0.312 22 58 60
Nate McLouth 10.61% 400 0.284 6 57 17 25
Jedd Gyorko 10.46% 303 0.254 8 37 26 1
Torii Hunter 10.24% 426 0.31 10 63 50 2
Brian Dozier 9.98% 364 0.231 9 42 37 8

Again we have a few people who stand out as taking advantage of their skillset best. Domonic Brown and Adrian Beltre should probably hit fly balls to muscle it out of the park. Even a healthy Matt Kemp could take advantage of a few more fly balls.

But the meat of the list is a bit problematic. Michael Brantley? Lorenzo Cain? Starling Marte? Alcides Escobar!! Brian Dozier?! Ben Revere. Ben Revere has hit five home runs in his entire professional career, dating back to 2007. He hasn’t hit one since 2011 and none at the big league level. He probably shouldn’t hit more fly balls.

Interesting also to see Torii Hunter on this list. Hunter talked to me about hitting more ground balls because he’s hitting in the two spot — “I’m a selfless player, not a selfish player” he said about hitting ground balls in order to move his teammates along on the basepaths and get on base more himself. Well, he’s looked to hit it out a bit more in June and July, and at least he’s shown the best slugging numbers of his year in those two months. It’s unclear which way is the best for him. He’s enjoyed great batting averages on balls in play these last two years with the new approach, and therefore his best batting averages. But it might be nice to get 20+ homers from him again in any given year. Especially since, as an older player, he’s more likely to benefit from muscling it out than relying on speed to make the most of his balls in play.

Mike Moustakas? With 7.5% more ground balls, he ranked 23rd in that sort of change. That was enough to get him from first in the league in fly ball percentage to seventh in the league. And it’s obviously working for him.

I expect a gift basket any day.

Comments (4)

  1. This post could use some editing…Domonic Brown, not Young, Starling Marte, not Starlin, and most egregiously – Ben Revere has 0 career home runs, I don’t know where you got 4 from.

  2. In that case, baseball reference says 5 – http://www.baseball-reference.com/minors/player.cgi?id=revere001ben

  3. It is worth noting that Revere was at .365/.390/.432 since June 1 until he broke his foot on a foul ball, so while you’d think it’s not a great idea for him apparently it was working.

    My guess would be early on he was purposely hitting grounders trying to use his speed but after his .456 OPS April went back to his natural swing and is making better overall contact.

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