Didi Gregorius Is in the Right Place and Time

Back when he was a minor leaguer, Didi Gregorius hit a combined total of 26 home runs. Gregorius is now the regular shortstop for the Yankees, who are a major-league franchise, and last week, he hit his 26th home run of this year alone, off of Ervin Santana. In Game 5 of the ALDS, Gregorius hit home run number 27, off of Corey Kluber. Two innings later, he hit home run number 28, also off of Kluber. Gregorius hits for power now, and while this feels like a fairly sudden development, it hasn’t been so sudden that Gregorius hasn’t been able to perfect the subtle bat flip. By now, Gregorius has hit enough home runs that he knows what they feel like right away.

It’s low, but it’s confident. It’s quiet enough that no opponent could get too upset, but still, it accomplishes the purpose. Gregorius concludes his home runs with a flourish. It’s behavior born only of experience. Gregorius has done this enough.

This isn’t something anyone imagined. When the Yankees traded for Gregorius, they just wanted an athletic young regular. A shortstop with range and a bit of bat control. Gregorius fit the profile, but between 2015 and 2016, his home-run output went from 9 to 20. This year it climbed only further still. Gregorius doesn’t look like a classic power hitter, and even when you go to the advanced numbers, it still feels like something is missing. It doesn’t make so much sense that he should do this.

The hardest ball Gregorius has hit this year was 106 miles per hour. Aaron Judge can get there on a bunt. Looking at things differently, there are 243 players who have hit at least 10 home runs that were tracked by Statcast. Gregorius ranks 240th in average home-run exit velocity, meaning he is fourth from the bottom. Gregorius isn’t absolutely clobbering the ball. In fact, courtesy of Baseball Savant, here’s his 2017 home-run spray chart.

Everything is going out to right field. It’s like a left-handed classic Brian Dozier. Gregorius has power only to his pull side, which is the hallmark of the low-power power hitter. The big-power types can hit the ball out to any direction. Someone like Gregorius has to be picky. But here’s the thing: A home run is a home run. A homer hit 95 miles per hour isn’t worth fewer runs than a homer hit 115. Gregorius has increased his launch angle year over year, to the point where his average angle this season was somehow higher than those posted by Evan Gattis, Kris Bryant, and Cody Bellinger. Gregorius is trying to hit fly balls. And he’s being rewarded, because now, in this home-run environment, Gregorius has just enough pop to make it work.

Even just a few years ago, when homers were harder to come by, one might’ve rightly criticized Gregorius for putting so many balls in the air. But ever since the middle of 2015, the ball has been flying, and it hasn’t made the same difference across the board. The players with the most power didn’t have much to gain. They were already hitting the ball plenty hard. What happened was that the home-run floor, so to speak, was lifted. Players didn’t need so much power anymore to drive a ball out of the yard. It made more sense for the middling types to aim for the fences. Gregorius’ power ceiling was raised. There was more for him to gain from putting the ball in the air.

So many different players are representative of the home-run spike. Even just sticking with shortstops, Elvis Andrus has some power now. So does Zack Cozart. So does Andrelton Simmons. So does Francisco Lindor. Gregorius is among them, and this season, he improved in terms of his selectivity. Not so much his pitch selectivity — Gregorius likes to swing, and he infrequently walks. But Gregorius understands that his fly balls only have a chance to right and right-center. So let’s look at how he’s progressed.

In this first plot, we’re looking at Gregorius’ rates of fly balls and line drives that were pulled. Instead of looking at the rates themselves, I’m showing percentile ranks among big-league hitters.

Gregorius started to pull the ball in the air more in 2015. Last year, he took a step back, maybe because he wasn’t sure if the ball would keep doing what it was doing, but this year, Gregorius has recovered, and then some. In terms of pulled air balls, Gregorius is up there in the 83rd percentile. He knows where the runs are.

Now I have a second plot. For this, I’ve isolated only batted balls hit to the pull side, and I tracked the rate of how many of those were grounders. Again, I’m showing Gregorius through the lens of his percentile ranks.

Just last season, 58% of Gregorius’ pulled batted balls were grounders. Those aren’t worth anything, especially as a lefty. This season, 44% of Gregorius’ pulled batted balls were grounders. That was one of the lowest rates in all of baseball. The majority of the time, when Gregorius went toward right field, he put a ball in the air. He’s not so much extremely pull-prone, and again, he doesn’t have exceptional power, but Gregorius has figured out how to maximize his offensive skillset in the era he’s playing in. In another time, Gregorius might’ve been instructed to hit more line drives and grounders. In this day, in this age, especially in the Yankee Stadium lefty environment, Gregorius’ power is sufficient. That’s not something that could’ve been predicted, I don’t think, but it is what it is. Gregorius has become something more than a regular. He’s become a franchise favorite.

We’re not to the point where Gregorius should be considered the best all-around shortstop in baseball. I can’t imagine he’ll ever be up there with Lindor or Corey Seager or Carlos Correa. Looking at the current projections, he’s just a little short of Trea Turner and Simmons. So, perhaps Gregorius isn’t even top-five. He might be. Or he might be top-six or top-seven. He’s in the upper third, in any case, blending his power with his contact and defense and running. Plenty of teams would kill for an upper-third everyday shortstop.

It’s a strange sign of the times that, when 2017 is complete, someone like Didi Gregorius might’ve hit 30 balls over the fence. But that’s not a criticism. That’s nothing against Gregorius’ skill. He’s making the most of what it is he has. You can’t really ask more of a player.