Zack Wheeler keeps getting better

It’s not exactly breaking news that Zack Wheeler has gotten better as the 2018 season has gone along. We touched on that notion back in the middle of June and again earlier this month, and over that span of time alone, he went from looking like a pretty good major league starter to a borderline ace. Since that last check-in, he’s been absolutely phenomenal.

After putting up a so-so 4.09 ERA in April, Wheeler had a downright awful 6.43 ERA in May. That left him with a 5.40 ERA through the first nine starts of his major league season. But he proceeded to put up a 3.26 ERA in June and a 3.13 ERA in July, the combination of which had other teams interested in trading for him before the non-waiver deadline, even though no deal materialized.

Since then, however, Wheeler has pitched better than ever before in his major league career. In four August starts, he has a 1.38 ERA and a 2.04 FIP, the latter of which is the result of having struck out thirty, walked only five, and given up just one home run in the month. He’s gone seven innings three times and five innings once, a far cry from the Wheeler of old, a pitcher who rarely completed the sixth inning.

Last we checked in on Wheeler’s trends, he had been gradually throwing his fastball harder—and less often—while continuing to increase the frequency with which he threw his slider and splitter. The rise of those two pitches correlated with the decline in his usage of his changeup and a relatively steady, but still low, usage of his curveball.

First, an update on the velocity: Wheeler has finally plateaued. He’s averaged 96.71 miles per hour on his fastball, according to Brooks Baseball, and that’s down just a touch from his 97.00 average in July. The rest of his pitches are right in line with their velocity norms from the past couple of months, too.

When it comes to pitch usage, though, Wheeler has made his most drastic change yet. According to the pitch classifications at Brooks, Wheeler has not thrown a changeup in August. Over the course of his career, Wheeler has never gone a month without throwing that pitch. To make up for that, he’s thrown his fastball 58.81 percent of the time—a bit more than in July but pretty much the norm this year—and has his splitter up to 10.48 percent, a new high.

Brooks Baseball

Getting back to the strikeouts, Wheeler’s 30.0 percent rate in August is elite. The league average for a starting pitcher this year is 21.4 percent. He’s gotten swings-and-misses on all of his pitches in August, with his fastball at a respectable 10.93 percent swinging strike rate and the thee offspeed pitches he has thrown much higher: 17.50 percent for the slider, 20.45 percent for the splitter, and 26.53 percent for the curveball. All of those rates for the offspeed pitches are better than they were in July, and save for a bit higher of a rate for the splitter in June, they’re all the best marks of his season. So let’s take a look at an example of each pitch doing its thing.

August 4: Nick Markakis strikes out on a splitter

This had been a long at-bat that saw Markakis foul off a slew of pitches and Wheeler make some throws over to first base. As much as Markakis battled, though, Wheeler finally finished him with this splitter, a pitch with beautiful movement.

August 20: Buster Posey strikes out on a slider

Posey isn’t his best self right now, but after getting him to 2-2, Wheeler drops this nasty slider on him. Posey probably thinks that pitch is going to paint the outside corner, which gets him to swing, but it moves just off the plate after Posey has made that decision.

August 10: J.T. Realmuto strikes out on a curveball

After falling behind 3-1 in the count, Wheeler got Realmuto to swing weakly and miss at a slider. He followed that up with this curve, which got a stronger swing from Realmuto but just as much of a miss.

August 4: Freddie Freeman strikes out on the high cheddar

Freddie Freeman is one of the best hitters in baseball, but you wouldn’t have known it after Wheeler set him up and blew this 99 mile-per-hour fastball past him. Wheeler didn’t only strike out good-to-great hitters in his four starts thus far in August, but he was clearly able to handle the best.