The Retooled Mike Clevinger Is Something to Behold

Before Cleveland Indians right-hander Mike Clevinger exited his second start of the season with an injury, he was throwing some of the most dominant stuff in baseball. He left his April 9 start against the Toronto Blue Jays with five innings of one-hit baseball under his belt, and over his first two starts combined, he had allowed no runs, surrendered just four walks, and struck out 22 batters in 12 innings. A strained muscle in his upper back, however, meant that the Indians would have to wait more than two months for him to return to the mound. In his first two starts back in June, he got roughed up to the tune of 12 runs allowed on eight hits, six walks, and nine strikeouts in 6.1 combined innings. Then the calendar turned to July, and Clevinger turned back into the version of himself he teased in April.

Since July 1, Clevinger has made nine starts. He has thrown 54 innings, struck out 74 batters, walked just 14, and allowed four home runs. His ERA of 2.17 in that timespan ranks 10th in the majors, but his 2.33 FIP is second, and his 2.55 xFIP is first. That kind of performance is no mere return to being healthy for the 28-year-old veteran; It’s the best he’s ever looked.

Clevinger finished his first three seasons in the big leagues with FIPs of 4.86, 3.85 and 3.52, respectively. In 72 innings this season, he’s lowered that all that way down to 2.47. That figure is weighted down by the lowest walk and home run rates of Clevinger’s career, but mostly, it’s down because his strikeout rate has skyrocketed. After entering 2019 with a career K/9 rate of around 9.5, he’s elevated that figure to over 13 to this point in the season.

That explosion in strikeouts coincides with a major step forward for Clevinger’s stuff in just the past year or so. Over the past three years, he has seen his average fastball velocity increase each season — not an easy task, considering that he didn’t break into the majors until he was 25 years old. Most pitchers lose a tick or two in velocity between their mid and late 20s, but Clevinger has gone the other direction. According to Statcast’s pitch data, from the beginning of the 2017 season until June 9, 2018, Clevinger registered an average fastball velocity of at least 94 mph in just two games, both of which were relief appearances. In starts, he tended to average 92-93 mph. Then, on June 14, his average fastball velocity spiked to 94.9 mph in a seven-inning, one-run, 10-strikeout performance against the White Sox. His average velocity was above 94 mph in three of his next five starts, and reached at least 93.9 mph in each of his final nine starts of the season. In those nine starts, his ERA was 2.03, and he struck out 63 batters in 53.1 innings.

In 2019, his velocity has gained even more steam. In his first start of the year, he averaged 94.8 mph. In his second start — the one in which he injured his back — he averaged 96.1 mph, then the hardest fastball of his career. After his return, he turned in average fastball velocities of 96.5, 96.5, and 96.8. He hasn’t dipped below 95.4 since. For the season, his average four-seam velocity sits at 95.9 mph, just one year after he averaged 93.6 mph, and two years after he averaged 92.5 mph.

Clevinger’s increase in velocity was spotted last September by T.J. Zuppe of The Athletic, who spoke with the righty about the changes he’s made. In the story, Clevinger discussed the mechanical flaws present in the way he pitched as recently as early 2018, and what he needed to correct in order to achieve the velocity he desired:

“I wasn’t using the right muscles,” Clevinger said. “I was taxing my body really, really fast, because I was throwing with all arm muscles. Once those got tired — and that happens fast because you’re just using that — it was like my velocity dipped.”

Clevinger’s improved mechanics and, subsequently, velocity, have yielded immediate results. Over the first three seasons of his career, Clevinger produced wFB values of -6.3, -0.9, and 0.5. This year, he has a wFB value of 5.1. On a per-100-pitches basis — or wFB/C — his fastball rates 23rd-best in baseball among all pitchers with at least his innings total, between teammate Shane Bieber and Clayton Kershaw. But while his fastball has been a big reason for his surge in production, it still only tells half the story. To get closer to the heart of why Clevinger has been so good in 2019, we need to talk about his slider.

The slider has always been Clevinger’s greatest weapon. When he first broke into the majors, it already had well above average horizontal movement, and he’s improved upon that every year since, currently ranking eighth in baseball with 8.3 inches of movement more than average. What’s new about the slider this year, however, is improved depth. This is the first season of his career in which his slider is producing above average vertical movement in addition to it fantastic horizontal movement.

Armed with more shape, Clevinger’s slider is as good as ever. He has a 9.0 wSL, and the fourth-best wSL/C in the majors, at 2.98. Only Max Scherzer, Justin Verlander, and the currently suspended Frankie Montas have gotten more out of each slider they’ve thrown this season than Clevinger has. And with opponents putting together an xwOBA of just .182 against it, there’s every reason to believe those results are legitimate.

Clevinger’s slider and fastball have worked in concert with each other splendidly. Because of its reputation, hitters already knew they needed to be wary of Clevinger’s slider even before his fastball picked up velocity. Now that his fastball is harder than ever, it’s become even tougher to sit on one or the other.

This is made more difficult by the fact that, just as Clevinger began adding velocity, he also began to find uniformity in his release points. These graphs from Brooks Baseball show just how much progress Clevinger has been made in releasing the fastball and slider from the same spot.

Since the middle of last season, Clevinger has gotten his vertical release points to run nearly identical, and since the end of last year, has done the same on the horizontal axis. That has made life miserable for opposing hitters.

Consider an at-bat from just last week against Red Sox shortstop Xander Bogaerts. Bogaerts is a really good player, second in the AL in WAR right now, trailing only, well, you know who. Take a look at where these two pitches — one a fastball, the other a slider — start, and where they finish.

If my pausing reflexes are on point, the differences are tough to spot, right? In both frames, Clevinger is in the exact same spot in his delivery, Bogaerts is in the exact same position in the batter’s box, and the ball is about the same distance from home plate. Keep in mind, too, that judging from the Brooks Baseball data, these were likely released from the same spot as well. Now, here’s where the first pitch ends up:

And here is the 0-2:

Bogaerts was never hitting that pitch, and he knew it. Yet, there he was, flailing. The Red Sox actually ran Clevinger from that game early, thanks to four runs on 11 hits in 4.2 innings. Of those 11 hits, however, none left the yard, and just three went for extra bases. That’s a pretty good encapsulation of Clevinger’s one weakness this season: Despite a career opponent’s BABIP of .287, he’s allowing a BABIP of .338. His numbers are great, and that’s in spite of his batted ball luck being the worst of his career.

Statcast calculates similar scores for every player in its database. For pitchers, it’s based upon the kind of contact they allow, along with their walks and strikeouts. The three most similar pitchers for Clevinger: Aroldis Chapman, Felipe Vazquez, and Kirby Yates. Those are three of the most dominant relievers in the game. The difference, obviously, is that Clevinger is a starter. In other words, Clevinger is throwing like a top tier ninth inning arm, but for five, six, or seven innings at a time. Because he missed more than two months of the season, his dominance this season has been quiet. But don’t be surprised if he continues to throw like this next year. If that happens, there’s a real chance he becomes the best pitcher in his league.