Life at the Margins: Kris Bryant’s Changing Changes

Kris Bryant never made much secret of the fact that he liked to hit the ball in the air. “I liked hitting home runs when I was little,” he told the Chicago Tribune last year. “To do that, you have to hit the ball in the air, so that’s why I caught on pretty quick to the idea of hit it high and hard.”

That approach—executed by way of a steeply uppercut swing—carried Bryant, with immodest success, through high school, college, and the minor leagues. The home runs came easy. Even in the big leagues, the harsh uppercut produced 26 home runs in 2015, Bryant’s rookie season.

But the swing had some consequences. One such consequence was that he struck out 30 percent of the time. That’s a lot—only two batters fared worse. But Bryant decided a long time ago that he could live with strikeouts if they came in exchange for home runs.

Which is why the consequence that bothered Bryant about his swing last year was this: his flyballs weren’t doing as much damage as you might expect them to. Last year, Bryant hit flyballs 45 percent of the time. That’s a lot, too—only five qualified hitters did so more often.

But the percentage of Bryant’s flyballs which turned into home runs was curiously small—just 16 percent. Thirty-six qualifying batters, many of them not nearly as big and strong as Bryant, converted flyballs into home runs at a higher rate. Last year, David Peralta was better at this than Kris Bryant.

And so Bryant decided to change his swing, apparently on the basis that it was affecting his results, especially at home. "I’ve committed to making a swing change just to be more flat with my swing," he told the Tribune this spring. “In order to hit a home run into the wind here [at Wrigley Field], it’s got to be more of a line drive.”

The plan, at least as laid out by Bryant, seemed simple enough: Bryant would lower his average launch angle at Wrigley Field—thereby lessening the chances that his flyballs would get knocked down by the wind—and increasing the number of home runs he hit at Wrigley Field.

Reasonable observers, then, might have expected to see the following out of Bryant this year: A decrease in the average launch angle of his home runs, especially at home, and an increase in the percentage of his home runs which came at home (as he converted outs from last year into home runs from this year). Oh, and an increase in home runs overall. Is that what we’ve seen so far?

Well, yes and no. Bryant’s home runs have gone up, and the percentage of his flyballs that he’s turning into home runs has gone up too—he’s at 27 percent in that metric now, solidly in the top 15 players in the league. The results, therefore, are there. Here’s the kicker, though: it’s almost certainly not because of launch angle on his home runs. Check it out:

Bryant’s overall launch angle on home runs, and his launch angle on home runs at home, barely changed at all from 2015 to 2016. And, even weirder, Bryant’s launch angle on home runs on the road actually changed dramatically—but instead of decreasing, it increased significantly from last year’s numbers.

So what’s going on? A few things, probably. First of all, I think that observers—and maybe Bryant himself—may have misstated the nature of his intended change. Last year, Bryant did have a much more uppercut swing at home than on the road, and this year he doesn’t. But that macro change has come by virtue of changes on the road, not at home.

Secondly—and this is the more important part, I think—Bryant has independently become more choosy about the pitches he swings at, especially at the bottom of the zone, where he has to really get under the ball (with a high launch angle) to drive it. Last year, Bryant swung at 81 percent of pitches in the bottom third of the strike zone. This year, he’s swinging at just 72 percent of pitches in the same location.

I suspect that it’s this change, more than any adjustment in launch angle, that is driving Bryant’s power surge in 2016. Indeed, last year, just half of Bryant’s home runs came on pitches in the top two-thirds of the strike zone. This year, 64 percent of Bryant’s home runs have come the upper two-thirds—and the ones that haven’t come there have come exclusively on pitches down and inside, instead of spread out all over the plate.

Now, of course, a better examination of this subject would discuss the changing relationship between Bryant’s swing angle on all pitches and his power performance. Because of a lack of data, we are, instead, comparing Bryant’s launch angle on home runs and his performance. That’s different. Maybe Bryant’s swing path really has changed, and we’re missing it here somehow. But for the moment, it’s hard to find evidence of the change Bryant claimed to make earlier this year.

For players like Kris Bryant, you stop talking about strengths and weaknesses and instead talk about choices and their results. This spring, Kris Bryant chose to flatten his swing path, and thereafter told people about it. Meanwhile, during the season so far, he’s hit an awful lot more home runs and struck out less. Those are some choices, and those are some results. But it’s not clear, for the moment, that they’re linked.