When the Yankees traded for Nathan Eovaldi over the offseason, they acquired one of the hardest throwing starting pitchers in the game. Yet Eovaldi was also one of the worst starters in the National League last season - he gave up the most hits in the NL along with sporting one of the worst ERAs at 4.47. Still, the Yankees saw enough promise - after all, you can't really teach someone to throw 98 MPH - to give up David Phelps and Martin Prado in exchange for some exciting youth, something this team has had very little of in recent years.

For the first two and a half months of the year, Eovaldi looked about like he did last year - hard throwing, but unable to get many strikeouts and giving up a lot of hits (and runs). Through his disastrous outing on June 16th, when he gave up eight earned runs in just two-thirds of an inning against his former team, Eovaldi posted a 5.12 ERA, 4.01 FIP, and let opposing hitters hit .326 against him. He only induced swinging strikes 7.8% of the time - the major league average is 9.7% - and batters made contact with nearly 90% of balls he put in the strike zone (league average is 86.9%). He had an above average home run to fly ball ratio of 11.9%, and while his won-loss record was inflated at 5-2, he clearly was not giving the Yankees the kind of starts they had hoped for. His great potential remained, but he was certainly still struggling to live up to it.

Since that shelling at the hands of the Marlins, though, Eovaldi has been much, much more effective. He is striking out a few more batters (6.75 K/9, up from 6.40), and his batting average against has fallen all the way to .240. His WHIP recently is 1.20, well below the 1.65 he posted over the first ten weeks of the season. Since mid-June, his ERA is 2.97 with a 2.46 FIP, and he's finally inducing more swings and misses (8.9% swinging strike rate). He's also neared league average on contact on pitches in the zone. And, perhaps most impressively, since the Marlins game, Eovaldi has given up exactly zero home runs in 33 innings.

What might be behind Eovaldi's turnaround? Part of it has to do with the fact that he is mixing his splitter in with his fastballs more often. Almost a quarter of the pitches he's thrown in the last month have been splitters, up from just 10.6% prior. He's also getting more horizontal movement, having it run farther in on righties to jam them, while shooting it away from the middle of the plate for lefties. His splitter velocity has also increased pretty dramatically recently, up from 85 miles per hour to a little over 89 on average over his past six starts. Using his fastball a bit less and his more effective splitter more isn't getting Eovaldi many more strikeouts, but it is getting hitters to make weaker contact - hitters have made hard contact just 25% of the time recently, compared to almost 33% of the time earlier in the year. His line drive rate is also down, from 24.0% to 20%.

Eovaldi came into the year with plenty of promise, but not a lot of demonstrated success at the major league level, and his rough start had many Yankee fans worried that perhaps they'd given up the mildly dependable Phelps and versatile Prado for little to nothing. However, since his worst outing of the season, Eovaldi has become a much more effective pitcher, and with pitching coach Larry Rothschild's help, he seems to be improving his tactical approach to pitching. If he keeps progressing (and hopefully starts going a bit longer in games, as he still struggles to get past the sixth inning), he should be a valuable rotation piece as the Yankees make their playoff push and, looking to the future, could be an important and skilled mainstay of the Yankee rotation for years to come.

Data from FanGraphs and Brooks Baseball.