Astros: Could Chris Devenski regain his All-Star form?

Could Houston Astros pitcher Chris Devenski regain his All-Star form now that he’s back on the roster?

We’ve been hearing about Chris Devenski’s impending return for a while, it seems, and now it has finally happened. The Houston Astros activated Devenski from the Injured List in advance of Friday’s game and optioned struggling reliever Joe Biagini to the alternate site.

Devenski has not pitched since allowing three runs in one inning on July 26, which was just his second outing of the season. The Astros placed him on the IL with elbow soreness and he has spent the past few weeks rehabbing at the team’s alternate site in Corpus Christi.

In his season debut on July 24, Devenski struck out three and allowed one hit in a scoreless inning, so perhaps the elbow troubles played a role in his bad outing two days later. We’ll see what the 29-year-old has in store coming off a pair of disappointing seasons in 2018 and 2019.

The obvious question remains, of course, whether he can recapture the success he found in 2016 and 2017 that made him an All-Star and a Rookie of the Year candidate. To answer that question, let’s take a dive into the advanced stats courtesy of Baseball Savant and Baseball-Reference.

What the Numbers Say

At first glance, 2016 and 2017 were clearly his best years, with a quick decline in 2018 and an even further slide in the wrong direction for 2019. His ERA and WHIP climbed every season in that span, so it seems like things have just been on a constant downhill slide.

But let’s look a little deeper. Devenski’s 2016 season, in which he posted a 2.16 ERA in 108.1 innings, is probably an outlier. He was helped by a career-low walk rate and an abnormally low home run rate, only allowing four homers all season. That rate is far below the rest of his seasons, including his All-Star 2017. So in that sense, expecting him to replicate 2016 would be unfair.

He actually had a career-high walk rate in 2017 but a career-low hit rate, and his 1.2 home runs allowed per nine innings is more of a reasonable expectation. He benefited from a career-best strikeout rate that year as well and managed a 2.68 ERA in 80.2 innings.

For 2018 and 2019, his walk rate stayed close to the same, and his strikeout rate went down slightly but was still plenty healthy. The main difference is his rates of allowing hits and homers took a jump, with his 1.7 homers allowed per nine innings being a little higher than one would like. That, coupled with the fact that he was simply allowing more hits overall, caused his ERA to jump north of 4.00 in each of those seasons.

The Arsenal

We’ll go pitch-by-pitch through his arsenal, and he’s thrown his four-seamer more than 40 percent of the time over the course of his career. His velocity actually increased in every season from 2016 to 2019, topping out at 94.7 mph last year. Yet in spite of that, the pitch’s effectiveness decreased.

Batters hit .211 and slugged .422 off the fastball in 2017, but those numbers jumped to .295 and .551 in 2018, respectively. It was worse in 2019, as batters teed off to the tune of a .306 average and .587 slugging off the four-seamer, and remember that’s in spite of increased velocity. Batters’ exit velocity off the pitch was also higher in 2018 and 2019.

But the increased velocity has coincided with decreased lateral movement. The horizontal movement on his four-seamer has gone down every year since 2017, so the pitch may have gained a little velocity, but it’s lost a little movement. Straighter and harder isn’t necessarily the way to go unless you’re throwing triple digits and can really blow it by people.

The changeup, which he uses between 30 and 40 percent of the time, is his best weapon. Batters hit only .145 off it in 2017 and .175 in 2018. They hit a career-high .208 off it in 2019, which still makes it an effective pitch, though not quite as dominant as in previous years. The average exit velocity and home runs allowed off the pitch weren’t abnormally high either.

From a movement standpoint, the horizontal movement hasn’t gone down, but the vertical movement took a slight dip in 2019. That seems to have corrected itself in the earlygoing in 2020, but it’s something to keep an eye on. Either way, I wouldn’t worry too much about the changeup.

Then there’s the slider, which he’s thrown around 20 percent of the time. It was most effective in 2016 when batters hit .079 off of it, but that number has gone up to .178, then to .250 in 2018 and .233 in 2019. The movement on the pitch has actually gotten better, though the velocity has gone down just a little. Since 2017, batters’ exit velocities have steadily gone down, so this doesn’t seem to be a problem pitch either.

The Results

Since 2017, Devenski’s groundball rate has gone down every year while his flyball rate has increased. His line drive rate the past two years was also higher than 2017. Hitters were generally doing a better job of getting underneath the ball, which makes sense given the shifting flyball/groundball splits.

Batters definitely barreled up the ball more frequently against him in 2019, and they whiffed on his pitches at a career-low rate as well. It’s interesting because he actually had a career-best first pitch strike percentage. But hitters made contact on pitches both in the zone and outside the zone more frequently than in any other season in his career.

It makes sense when you think about how his pitches changed. When your fastball is a little straighter and your changeup doesn’t dive quite as much, hitters aren’t going to miss them as often. The changes to the pitches aren’t huge, but there’s not much margin for error in this game. The smallest thing can make the difference between a home run and a flyout.

If you’re thinking he’s leaving more pitches over the plate, you might be surprised. The percentage of his pitches that would be described as a “meatball” pitch (i.e. right over the middle of the plate) actually peaked in 2017 and was lower in 2018 and 2019. So Devenski’s problem doesn’t appear to be control-related, at least not to a large extent.

You also have to look at the context. The 2019 season was an outlier for the league in terms of home runs, with an abnormally large number of them hit, at least partially due to a change in the baseballs. At times, it seemed like all a hitter had to do was get the barrel to the ball and get it in the air and he’d have a home run. That surely couldn’t have helped Devenski either.