Jacob deGrom and looking beyond fastball velocity

Everyone focuses on the velocity that the Mets young pitchers have and no doubt that’s a wonderful thing. But what gets lost sometimes in that radar gun lust is how all four of their hurlers come with diversified repertoires. All four throw four pitches on a regular basis. According to PITCHf/x, Jacob deGrom complements his fastball with a slider, which he throws 17.6% of the time, a curve (12%) and a change (9.7%).

So far this year, deGrom is 3-1 with a 2.62 ERA. But everyone will tell you that he hasn’t been as good this year as he was last year. Most everyone will point to his velocity and it’s easy to see why. In 2015, deGrom averaged 95 mph with his fastball and this year it’s down to 92.8, a significant drop. Two starts ago, we saw the best velocity this year from deGrom, who averaged 94.1 with his fastball against the Dodgers. But last time out his velocity fell back to 92.7, essentially his average for the year.

Yet both of those starts were strong ones for deGrom, who went 7 IP and allowed 1 ER in both.

In the game against the Dodgers, Linear Weights showed deGrom’s fastball was not as effective as its velocity might indicate, at least from a strictly result-of-the-pitch point of view. He had a (-0.4) wFB for the game. Instead, it was his slider which got results, as when he threw that breaking ball, deGrom had a 2.6 wSL.

Still, one could argue because deGrom had the extra velocity in that game, it made his slider that much more effective.

In his next outing against the White Sox, deGrom did not have the fastball velocity yet he still threw the pitch 70.9% of the time and Linear Weights showed it as an overall plus pitch for the day, with a 1.6 rating. While his slider was so effective against the Dodgers, this time his curveball was his go-to off-speed pitch, as deGrom threw it 14.6% of the time and had a 0.5 Linear Weights value for the game. He threw his slider the least of all, just 4.6% of the time.

The fastball velocity has absolutely been a problem but what gets overlooked is that his off-speed pitches haven’t been consistent, either. So far in nine starts, deGrom has yet to have a game where all four pitches registered as positive offerings by Linear Weights. He’s had three games where he had no more than one negative offering and he’s allowed just 2 ER in 19 IP in those outings.

Yes, a little bit of that is circular. It’s no surprise that the results have been good for deGrom when he has three pitches working for him. But it reinforces the idea that it’s more than just the fastball. In those three games, his average fastball was 92.8, 92.9 and 91.9 mph.

Last year, deGrom had 15 outings with no more than one negative offering, including seven where all four pitches had positive ratings from Linear Weights.

Here in 2016, the change has been the off-speed pitch that deGrom has struggled with the most. Again, that makes sense, given his fastball velocity hasn’t been what we got used to last year. In the last two outings in which overall he’s been so good, deGrom’s change has been in negative numbers in results. Last year there was a 9.5 mph difference between his average fastball and average change. This year the overall number is 8.2 mph. There’s not been one game where his separation was even 9.0 mph.

Might deGrom be better off scrapping the change until his elite fastball velocity returns on a regular basis?

He essentially did that in one game. On May 15 in Colorado, deGrom threw his change just 2.9% of the time. It was also the day he had his lowest average velocity (91.4) with his fastball. For the environment, it was a solid start, as deGrom allowed 3 ER in 6.1 IP in Coors Field, with one of those runs being allowed by a reliever.

One other idea to consider is that when Rene Rivera is behind the plate, deGrom has allowed 1 ER in 13 IP and has limited batters to a .510 OPS. He has a 3.50 ERA and a .726 OPS in six games caught by Kevin Plawecki. Rivera caught his last outing, the one where he had seven strong innings against the White Sox, even without 2015 velocity.