David Peterson is Due for Improvement in 2022
There have been many complaints around the league about the change in the baseballs that is depressing offense and reducing home run rates. However, if there is one fanbase that should welcome that change, it is that of the Mets. Though its sustainability is dubious, the Mets have been able to find offensive success without relying on home runs, currently (as of the morning of May 25) sitting at 2nd in baseball in runs (219) despite ranking 20th in home runs (38). On the other side of the ball, the deadened balls have helped Mets pitchers who are most vulnerable to the home run perform well above expectations. And while the Mets’ pitching staff has once again been devastated by injury, David Peterson, after pitching to a disappointing 5.54 ERA last year, is stepping up in a big way.
The combination of deadened balls and pitcher-friendly dimensions has made Citi Field a paradise for fly-ball pitchers in 2022. Last year, Peterson’s biggest problem was an exorbitant 22.4% HR/FB%. His xFIP—which estimates a pitcher’s ERA with a league-average HR/FB%—was an encouraging 3.93. Unfortunately, the difference between Peterson’s ERA and xFIP was not solely due to luck. While the league average fly ball distance, according to baseball savant, was 318 feet with an average exit velocity of 92.2 mph, fly balls hit against Peterson averaged 334 feet with an average exit velocity of 94.6 mph. As you might expect, Peterson struggled mightily outside of Citi Field, posting a 7.97 ERA in 35 innings on the road and a 2.84 ERA in 31.2 innings at home. Those home/road splits almost certainly overstate the impact Citi Field’s dimensions had on Peterson, but it supports the idea that Peterson benefits more from far fences than the average pitcher. In 25 innings with 2022’s deadened balls, Peterson’s HR/FB% has plummeted to 8.7%. As a result, despite little change in xFIP (3.93 to 3.85), Peterson’s ERA has dropped to 2.16 in 2022. The deadened balls don’t have such drastic effects, and much of this change is due to a decreased average exit velocity (94.6 to 88.7 mph) and average distance (334 feet to 299 feet) on fly balls. Peterson’s flyball metrics will likely regress towards his career numbers as the season progresses, but deadened baseballs should keep his HR/FB% below its 2021 mark.
Another source of hope for Mets fans is Peterson’s improved slider. According to baseball savant, on sliders in 2022, Peterson has increased his average velocity from 82.1 mph to 84.3 mph, his vertical movement relative to velocity from 1 inch above average to 2.1 inches above average, and his horizontal break from 5.3 inches to 6 inches. Last Monday against the Giants, Peterson recorded an average slider velocity of 85.5 mph (the highest of his career), which helped him induce a very good 38% CSW on the pitch. The pitch has gotten much better results in 2022, as the table below shows:
| Average MPH | Run Value | wOBA | Whiff% | xwOBA | Hard Hit% | Barrel% | GB% | LD% | |
| 2021 | 82.1 | 5 | .393 | 37.2% | .379 | 46.2% | 15.4% | 41% | 35.9% |
| 2022 | 84.3 | -3 | .131 | 52% | .194 | 50% | 0% | 50% | 20% |
While Peterson has never thrown his slider this hard in his MLB career, the small sample size should not be ignored. Only so much can be concluded from 25 innings. However, deadened balls and a better slider should give Mets fans hope that Peterson can continue to find success in 2022 and be a good stopgap for an injury-plagued pitching staff.
