The bullpen version of deGrom is making K history

August 4th, 2022

Imagine having Jacob deGrom in your rotation and in your bullpen. That's basically what the Mets have right now with .

Díaz not only has 23 saves and a 1.51 ERA for the first-place Mets, he has 84 strikeouts in 41 2/3 innings. That's an 18.1 K/9. If the season ended today, he'd be the first pitcher ever to strike out over two batters per inning over as many innings as he's thrown. Díaz has struck out 52.5% of the batters he's faced, currently tied with Aroldis Chapman in 2014 for the single-season strikeout rate record.

To do this, Díaz has harnessed his fastball/slider combo in a way that would make deGrom proud. With the same type of explosive stuff, he's co-opted an element of deGrom's approach and tailored it to himself, and it's letting the Mets' closer overmatch hitters like their ace.

Let's compare Díaz's four-seamer and slider in 2022 to deGrom's in '21.

2022 Díaz -- 99.0 mph avg., 102.6 mph max, 23% thrown 100+ mph
2021 deGrom -- 99.2 mph avg., 102.0 mph max, 26% thrown 100+ mph

2022 Díaz -- 90.6 mph, 29.3 inches of drop, 1.4 inches of break
2021 deGrom -- 91.6 mph, 28.9 inches of drop, 4.7 inches of break

Comparing those two pitches, step by step -- Díaz's arsenal vs. deGrom's most important combo -- reveals how Díaz has not only reattained the elite closer status he reached in 2018 with the Mariners, but become even more dominant now than he was then. Let's break it down.

The similarity in the fastball is the big velocity.

Díaz, like deGrom, has raised his fastball velocity from "high" to "elite." His four-seamer is nearly two mph faster than when he joined the Mets in 2019, increasing from 97.4 mph to a career-high 99.0 mph in 2022. That mirrors deGrom's increase over the same period, to his own career-high 99.2 mph last year.

The key for Díaz, though -- like for deGrom as he rose to "best starter in baseball" territory -- isn't the average, it's the high end. Díaz is hitting the extreme end of velocity way more often than he used to, and extremely fast fastballs are just a lot harder to square up.

Díaz's % of fastballs thrown 100+ mph by year
2018 (Mariners): 0.3% (2 100+ mph pitches)
2019 (Mets): 2.0% (14 100+ mph pitches)
2020: 0.7% (2 100+ mph pitches)
2021: 13.8% (86 100+ mph pitches)
2022: 22.9% (67 100+ mph pitches)

Díaz hit a career-high 102.6 mph on June 25. And when he needs to put a hitter away, he dials it up. Díaz's fastball strikeouts this season have averaged 100.1 mph. That's gas.

The similarity in the slider is the pitch profile.

Both Díaz and deGrom throw sliders with tight downward movement and outlier velocity for a breaking pitch. It's not the "sweeper" style of slider in vogue around baseball; it's the slider/cutter hybrid that complements a power four-seamer.

Díaz was throwing his slider around 89 mph when he first got to the Mets; now it's closer to 91 mph. As it's gotten harder, Díaz also made it more of a vertical pitch like deGrom's. Normally, as a pitch gets faster, it can lose drop, since gravity has less time to act on it as it gets to the plate. But Díaz's slider, at its highest velocity ever, has added two inches of drop from last year (27.4 inches) to this year (29.3 inches).

Hitters are swinging and missing at Díaz's slider over half the time. He's gotten 65 of his 84 K's on the slider, over three quarters of his total. The average velocity of those strikeouts is 91.1 mph, and 53 of them have been over 90 mph.

Most 90+ mph K's on non-fastball pitch type (through July)

  1. Edwin Díaz's slider: 53
  2. Sandy Alcantara's changeup: 52
  3. Sandy Alcantara's slider: 28
  4. Shohei Ohtani's splitter: 24
  5. Emmanuel Clase's slider: 23

Who do you think was leading the league in 90-plus mph strikeouts on a secondary pitch type at this time last year? deGrom, who had 63 K's on 90-plus mph sliders. When he last pitched at the end of the first half, the next-closest pitcher was Zack Wheeler, with 40 K's on the power slider he developed when he was deGrom's rotation-mate with the Mets.

The similarity in the combo is the tunneling.

Díaz puts his two pitches together á la deGrom: by attacking the left edge of the plate.

Díaz's slider is the real out pitch, and he gets those outs by going to the traditional slider dead zone, down-and-away to a right-handed hitter/down-and-in to a lefty. To set up that pitch -- or vice versa, if he's pitching backwards off the slider -- he takes a page out of deGrom's book and elevates the fastball right above it to the same side of the zone.

With his slider more of a down-breaking pitch now, Díaz gets some beautiful tunneling with his four-seamer. Does it look familiar?

If you look at the strikeouts Díaz is getting off his fastball/slider combo this year, and the ones deGrom was getting off his fastball/slider combo last year, they come in at nearly the same velocity and location.

Díaz and deGrom's fastball K's
2022 Díaz -- 100.1 mph / 2.89 feet high
2021 deGrom -- 99.7 mph / 2.92 feet high

Díaz and deGrom's slider K's
2022 Díaz -- 91.1 mph / 1.51 feet high / 0.59 feet to the glove side
2021 deGrom -- 91.5 mph / 1.49 feet high / 0.86 feet to the glove side

deGrom got strikeouts in 45% of the plate appearances ending on either pitch of that combo in 2021; Díaz has gone even higher in relief with the near-53% strikeout rate he's running in 2022.

The difference that makes Díaz stand out is the usage.

Here's what makes Díaz unique: the volume of sliders.

Díaz used to mimic deGrom in his pitch mix, predominantly attacking with four-seamers and throwing his slider off of that. In his first year with the Mets, when he gave up 15 homers and struggled, he was throwing two-thirds fastballs to one-third sliders. Even last year, he was still throwing 62% fastballs and 38% sliders, close to deGrom's 2021 usage of 57% four-seamers and 33% sliders.

This season? The combo is flipped. Díaz is throwing 55% sliders and 45% fastballs, the first time in his career he's ever thrown more breaking balls than heaters.

Let's take a look at the change in Díaz's approach in different situations.

First pitch
2021 deGrom -- 72% 4-seamer, 22% slider
2021 Díaz -- 70% 4-seamer, 30% slider
2022 Díaz -- 57% 4-seamer, 43% slider

Ahead in count
2021 deGrom -- 51% 4-seamer, 41% slider
2021 Díaz -- 60% 4-seamer, 40% slider
2022 Díaz -- 38% 4-seamer, 62% slider

2 strikes
2021 deGrom -- 43% 4-seamer, 46% slider
2021 Díaz -- 57% 4-seamer, 41% slider
2022 Díaz -- 26% 4-seamer, 74% slider

Díaz and deGrom both have an elite four-seamer and an elite slider. It's the same dominant two-pitch combo. But Díaz has made that combo his own this year, and the historic strikeout numbers are the result.