It’s cliché to say that baseball is a game of adjustments, but I’m a lazy writer, so I’ll say it anyway. For any player to remain at a given standard of play — whether it’s stardom, adequacy, or even replacement level — they can’t just stay static. Their opposition will discover their weaknesses and avoid their strengths, so they have to work to counterbalance them. Insanity, in baseball, is doing the same thing over and over again and expecting the same results.
A fringe prospect in the minors, Jacob deGrom has had a remarkable run for the Mets. From 2014 to 2016, he put up a 73 ERA- (seventh in the majors) and 74 FIP- (sixth) in 479 1⁄3 innings of work. But if he kept doing the same thing over and over again, hitters might figure him out. So deGrom’s made a change to the way he pitches, and the results have been pretty spectacular.
First, let’s look at those results. During his first three seasons, deGrom had the 11th-highest whiff rate in baseball, at 11.8 percent, which played a role in his 25.6 percent strikeout rate. His ground ball rate was a respectable 45.3 percent, placing 63rd among 132 qualifiers. Combine that with a top-notch 6.1 percent walk rate, and you get a great starting pitcher.
What if deGrom wants to be better than great, though? What if he wants to be elite? Then he’d need to pump his strikeout rate up to 30.6 percent (thanks to a 14.9 percent whiff rate) and improve his ground ball rate up to 60.3 percent ground ball rate, all while keeping his walk rate around, say, 5.6 percent. That oddly specific hypothetical has come to pass thus far in 2017. The new high-strikeout, high-ground ball version of deGrom has a 51 ERA- and 66 FIP-, and while the year is still young, those are clearly massive steps forward.
Now, for the background. From 2014 to 2016, when deGrom was flying high, he made his four-seam fastball his primary pitch, mixing in a slider, sinker, curveball, and changeup for good measure. That’s not how things have gone this year:
While the curve and change have each remained secondary pitches, the other three offerings have moved around, as deGrom has replaced his four-seamers with sinkers and sliders. Looking at the outcomes on those offerings, you can understand why he’d make that switch.
What does a pitcher want from his sinker? Ideally, it’ll result in a ground ball — and that’s just what deGrom’s has done:
What does a pitcher want from his slider? Ideally, it’ll result in a whiff — and that’s just what deGrom’s has done:
Each of those pitches has become elite — the sinker ranks third in grounder rate, and the slider places sixth in whiffs per swing. This isn’t to take anything away from deGrom’s four-seamer, but that pitch just can’t compare to his sinker/slider combo.
deGrom isn’t the first Mets pitcher to alter his strategy this year. Through four starts, Noah Syndergaard has relied on his sinker and slider more than ever. My BtBS colleague Shawn Brody explained why Thor made this change, and the reasons for deGrom — nasty movement on the sinker, and crazy velocity on the slider — are pretty much the same.
For some time now, the Mets have one of the better rotations in baseball (when healthy). The team’s starters led the majors in fWAR last year and ranked fourth the year before. Just because they’ve been one of the best, though, doesn’t mean they can’t get better. Both Syndergaard and deGrom have messed with success, and they’ve looked more dominant than ever because of it.
All data as of Thursday, April 20.