Nathan Eovaldi, for lack of a better description, is a statistical oddity. He holds a 13-2 record, including wins in eight straight decisions. His ERA has plummeted from 5.12 after being shelled by the Marlins on June 16 to a more reasonable 4.24 after Wednesday’s win vs. the Twins. But his ERA seems a little high relative to his win total. Eovaldi is one off the major league lead (entering Thursday) and has received the 4th-best run support of all qualified starters. That may explain the wins, but what lies underneath is a strange mix of advanced statistical numbers that, fortunately, point to a pitcher who resembles the “Nasty Nate” Yankees fans hoped he could be rather than the pitcher who had an ERA over 5.00 earlier this season.
Eovaldi is already an unusual case because he has the highest average velocity on his fastball among all qualified starters, averaging 96.4 mph. That’s nearly a whole mile per hour faster than anyone else. High fastball velocity usually equals high strikeout totals, but the righty has only 100 K’s in 136 innings pitched. His fastball has a below average swinging strike rate and horizontal movement. Matthew Kory did a comprehensive piece on this detail for Fangraphs in June, which comes to the conclusion that Eovaldi’s fastball is more hittable because of these factors. His fastball could be dominant, but because of how straight it comes in to hitters, it’s more hittable than it should be.
The more standard advanced metrics point to an eventual improvement in Eovaldi’s performance. His .337 BABIP by opposing hitters is the 4th highest rate among qualified starters. Meanwhile, Eovaldi has induced just under two ground balls for every fly ball, good for 17th among all qualified starters. Given his tendency for ground balls and the fact that ground balls are the most susceptible types of batted balls to luck, this shows that Eovaldi has suffered from bad luck overall this season.
Despite a 4.24 ERA this season, Eovaldi’s FIP and xFIP show room for improvement, as they stand at 3.52 and 3.80, respectively. The xFIP may inflate Eovaldi’s expected numbers, as xFIP is calculated with a 10.5% home run/fly ball ratio, while his career average is 7.2%. His 3.52 FIP may be a more accurate assessment of where the 25 year-old should be right now, and assuming his BABIP adjusts to a more reasonable number and more of Eovaldi’s ground balls find their way into gloves rather than through the grass, his ERA should come more into line with his FIP.
Considering his relatively young age and raw talent, Eovaldi could still bloom into a front-end starter. If he can develop movement on his fastball, he will likely be able to generate more strikeouts. If he can do that while continuing to keep the ball on the ground, he will have the stuff and the makeup of at least a #2 starter for the Yankees.
Right now, though, expect Eovaldi to put up lines similar to the ones he has put up so far. Joe Girardi appears hesitant to pitch Eovaldi deep into games, as he has only completed seven innings or more twice during the eleven-start span in which he has assembled his eight consecutive wins. He has thrown strikes for over 67% of his pitches this season, but more often than not, hits the 100 pitch mark pretty early in his starts, making his line appear more inefficient. BABIP luck has something to do with some of that, and if that adjusts, Eovaldi may be able to work more efficiently and go deeper into games.
Wins are fluky, but Nate Eovaldi has been lucky to get consistently solid run support from the Yankees offense. But his other statistics show that he is still a solid, above-average pitcher even if he becomes less lucky in the win column. But if the Yankees can keep up the run support and he gets more luck, Eovaldi will still win frequently no matter what.
