The Mets' starting pitching corps has been a top-three unit in ERA, FIP and WAR across the entire MLB since June 22. The team has gone 23-16 (.590) over that stretch and clawed back into legitimate playoff contention thanks in large part to the team's three units (hitters, starters, relievers) coming together at the same time.
But what's so special about June 22? That was the day that Zack Wheeler turned his season around. A player all but assured to be traded by the deadline in late July, Wheeler instead tapped into his potential and went from trade bait to a building block for the 2019 Mets, and maybe beyond.
Over Wheeler's last seven starts, he has gone 4-1 with a 2.62 ERA. That's good for a 1.6 WAR. Consider that Wheeler's collective season WAR before June 22 was 1.8. This means that Wheeler has provided equal value over his last seven starts as he did over his first 15. That's marked improvement.
It's been clear even without the sabermetrics. Particularly over his last two starts, a stretch of 15 scoreless innings with 12 strikeouts and just one walk, Wheeler just looks more comfortable on the mound. He's going deeper into games, giving up less home runs and throwing harder than he ever has in his career.
A couple of mechanical changes have helped Wheeler achieve this success. For one, he's throwing more sliders, a trend that new pitching coach Phil Regan seems to have instructed Jacob deGrom, Noah Syndergaard and Steven Matz to do, too. Opponents have hit just .115 off Wheeler's slider since July, so it's working. Why, though?
Wheeler's pitch placement has really tightened up over his last seven starts. Take a look at these heatmaps below, the first one taken over Wheeler's first 15 starts and the second one taken from his seven most recent starts (courtesy FanGraphs):
Notice how there's a lot more dark red and orange lower in the zone in the picture on the right? Those pitches are harder to square up and drive in the air, which helps explain the drop in home run rate. Wheeler is also pitching inside more with his fastball, which helps set up those sliders down and away. It sounds simple, but Wheeler is hitting his spots much more efficiently lately, which has made him more aggressive and harder to hit.
The Mets could have simply cashed in and traded Wheeler. Rumors indicated that the Mets had a high asking price, and rightfully so. Wheeler had begun showing signs of turning things around for the Mets, and now he is an integral part of what looks to be the deepest rotation in baseball.
The Mets deserve major credit for completing a turnaround that almost nobody thought was possible. However, things will get more difficult for them to finish the job. 10 of the team's next 11 series are against teams either in a playoff position or less than 1.5 games back of a spot. As much as the team's 23-16 run since mid-June has saved their season, the team's next stretch will define it.
And Mets fans should be thankful that they still have Wheeler taking the mound every fifth day to help the team continue its remarkable run.