clock menu more-arrow no yes

Filed under:

Jacob deGrom's mechanics could be affecting his stuff

New, 28 comments

deGrom hasn't looked quite like himself yet this year, and it may be because of a mechanical issue.

Jake Roth-USA TODAY Sports

Jacob deGrom has a 1.99 ERA through four starts in 2016, but that doesn't tell the whole story. deGrom hasn't quite resembled the incredible ace pitcher that he was last year, and it's reflected both in watching his starts and in some of his peripheral statistics. The sub 2 is at least partially a component of the quality of competition he's faced through 4 starts: the Phillies, Braves and Padres have three of the four least productive offenses in baseball. His strikeout rate has dropped significantly, from 27.3% last year to 17.2% this year. According to pitch F/X, his pitch velocities, most notably his fastball and slider, are also significantly down from last season:

Avg. Velocity Four-seam Slider
2015 94.9 mph 89.6 mph
2016 92.6 mph 87.2 mph

Like Matt Harvey, deGrom has occasionally had problems holding his velocity during his starts this year. According to TrackMan, deGrom's fastball averaged 94.4 mph in the first inning Thursday night against the Padres, but fell to 92.6 mph in the fifth inning, his last.

Last Saturday, Hall of Fame pitcher John Smoltz observed during the Fox Sports 1 broadcast that deGrom's arm slot has dropped from 2015, and that he isn't getting on top of the ball as much. Smoltz said that this can flatten his stuff out and make it more hittable.

deGrom mentioned something similar after his start against the Padres, telling reporters:

I came in and watched some video right after I came out, and it's quite a bit lower than it was last year. Last year, my elbow was above my shoulder. This year, it's not even getting close to getting above it.

Checking PITCHf/x, deGrom's vertical release point is lower than last year. In the first half of last season, deGrom's average vertical release point was about 5.85 feet. This year, it's about 5.61 feet.

deGrom further expanded on his mechanical issues. He cited the fact that his front shoulder is flying open and that he's falling off towards the first base side as he delivers the ball, compounding his problems.

My stride is towards the first base side. I don't know if you've seen how far I'm falling off towards first base...when Dan came out to the mound, he's like, I don't care how hard you throw the ball, just try not to fall that way, because that puts a lot of stress on places it doesn't need to be.

deGrom told reporters that he believes he can fix the mechanical problem during sessions between starts.

Despite the fact that deGrom did not pitch well against the Padres last night, there are at least some encouraging signs building for him related to his stuff. According to TrackMan, his max four-seam fastball velocity has increased from 93.9 mph in his first two starts to 95.4 mph in his last two, an increase of 1.5 mph. In his first two starts, he threw 0% of his fastballs 94+ mph. In his last two starts, he's thrown 21.6% of his fastballs 94+ mph. deGrom is also maintaining about the same swinging strike rate and contact rate as last season despite the drop in strikeouts.