Zack Wheeler pitched a seven inning, 10 strikeout gem on Monday night, dropping his ERA to 3.63 and looking every inch like the ace the Mets hoped for when they acquired him back in 2011.
To say Wheeler's career has had its ups and downs would be an understatement -- two years lost to a rough Tommy John recovery and a disappointing and injury-shortened comeback in 2017 raised serious questions about whether he still belonged on a major league mound. But over his last 15 games, he's pitching better than ever before and he's succeeding on the basis of sustainable, meaningful improvement that bodes well for the 28-year-old moving forward.
The most notable hallmark of Wheeler's step forward is his efficiency, which has always been a challenge for him. While he's had a handful of other 15-game stretches with a lower ERA than the 2.71 he's put up during this stretch, his average of over 6.1 innings pitched in those 15 starts is a career-best.
Behind this newfound ability to go deep into games is another important improvement for Wheeler: cutting down on the walks. Control has always been a challenge for him and while his 2.89 walks per nine innings is not an elite number, it's much better than the league average and a significant improvement over his career numbers.
The biggest change for Wheeler isn't that he's hitting the strike zone more often, but rather that he's fooling batters with better movement and generating swings and misses. This is a very positive sign because it suggests that he's not trading control for hittability.
Another positive sign, both for Wheeler's effectiveness as well as his health, is his velocity, which has rebounded impressively from a concerning dip last season. His fastball is averaging a sizzling 96.8 miles per hour going back to the beginning of June, with his slider at a career-high 91.5 miles per hour over the same stretch.
But the biggest story behind Wheeler's pitch repertoire was the introduction of a splitter back in May. Though early attempts to incorporate it were rocky, and may have contributed to early-season struggles, it has become a potent weapon for him, holding opponents to a .480 OPS.
The introduction of a fourth above-average pitch (his curveball is also a solid offering) is a major reason batters are struggling to get a good read on what Wheeler is throwing. Even when there's a bigger body of scouting reports on this new look from him, his easy delivery and ability to dial up the velocity on the fastball when he needs it will prevent the league from adjusting very much.
With a career marked by inconsistency and missed potential, it's easy to be worried that this is another illusion for Wheeler, but all signs point to a legitimate change in his game for the better. Instead of squeaking by on smoke and mirrors, or stringing together a few five-inning four-walk tightrope performances, he's showing the goods night in and night out, with the peripherals to back it up. The only question remaining is just how much better he can get.