Tomlin Has a 3.81 ERA? You Must Be Joshing!

The Indians have an awesome starting rotation. They’re fifth in the MLB (first in the superior-hitting American League) with a 3.95 SIERA, seventh in ERA with a 3.96. They obviously have a solid top three in Carlos Carrasco, Corey Kluber, and Danny Salazar. Beyond them, the emergence of Trevor Bauer has grabbed headlines. But what about that last spot in the rotation? It is being held down, and held down steadily, by one Josh Tomlin. And he isn’t dragging down the staff’s ERA like most number 4s and 5s. In fact, he’s actually improved the ERA of the staff with a solid 3.81 ERA. However, he’s only averaged 6.39 K’s per nine innings, far below the league average for starting pitchers this year (7.72). He certainly doesn’t have overwhelming stuff. How has he been able to succeed?

Tomlin has impeccable command. He’s walking 1.15 guys per nine innings, in line with his career (1.45). He’s third in the MLB in K/BB ratio (first in AL). He’s 13th in first-pitch-strike percentage. He dots the corner with his main secondary offerings, a curve and a cutter, throwing them down and away to righties and down and in to lefties. He’s done this throughout his career:

And he’s continued to do so this year:

He owns that low and outside corner! Spotting his pitches on the corners has likely helped Tomlin to induce a solid Z-Swing percentage of 62.7% (according to FanGraphs plate-discipline data), which is 10th-lowest in the MLB this year. This means that Tomlin has been good at getting called strikes. He pairs this skill nicely with a 33.6% O-Swing percentage, which is the 11th-highest in the MLB this year. This means that Tomlin has been good at getting hitters to swing at pitches outside of the zone (pitches they usually can’t drive). This has been a skill for Tomlin throughout his career (33.2% O-Swing during his career).

In addition, he has a career BABIP of .274 (league average is around .295 every year). He has improved on that mark this year, allowing a .268 BABIP. This isn’t entirely surprising, given the high O-Swing percentage: If you swing at pitches outside of the strike zone, it’s much harder to make solid contact. Also of note is the fact that Tomlin’s Z-Swing percentage has really improved for him this year (66.3% career versus 62.7% this year).

What’s the driving force behind the improvement in these two plate-discipline stats? Tomlin’s cutter and curve offer a good explanation. According to PITCHf/x data on FanGraphs, Tomlin’s cutter has the 15th-best “rise” among qualified pitchers this year. It also has the eighth-most horizontal movement, darting away from righties and in to lefties. What’s more, the cutter has induced a 42.7% O-Swing percentage across his entire career. That number has held strong this year at a 44.5% clip. He’s decided to uptick the usage on the pitch this year to a career high, while throwing his four-seamer at a career-low rate.

The curve is the driving force behind the low Z-Swing percentage: This year, the pitch has a crazy low percentage of 44.7%. While that is lower than his career percentage on the pitch,  the curve is generating excellent vertical drop this year (15th-best in the MLB), and I wouldn’t be surprised to see him maintain a low percentage.

Tomlin isn’t flashy. He doesn’t pile up strikeouts. He doesn’t throw very hard. But, he spots the ball tremendously well and appears to have good contact management skills. Two pieces to the puzzle are his low Z-Swing percentage (fueled by the curve) and high O-Swing percentage (fueled by the cutter and its uptick in usage).

Data courtesy of FanGraphs and Brooks Baseball. Thanks for reading!