With all the excitement surrounding the 2015 Mets' season, Zack Wheeler sometimes gets lost in the shuffle. Many believe that the season hinges on David Wright returning to form and Curtis Granderson and Michael Cuddyer putting up decent numbers in the outfield. Fans are excited to witness Noah Syndergaard’s electric stuff. They're anxious to see whether Matt Harvey will return better than ever and whether Jacob deGrom can follow up his rookie season and settle in as a front-line starter. Yet with all the hullabaloo surrounding these big names, Zack Wheeler may be the lynch-pin to the Mets' success.
Wheeler's development is normal
Maybe Wheeler sometimes gets overlooked because he is following a more common route to major league success than did Harvey or deGrom. Those two pitchers came out of the minor league system with little pomp and circumstance, and promptly exceeded expectations in spectacular fashion. Wheeler, on the other hand, was MLB.com’s sixth-best prospect before the 2013 season, sandwiched between Trevor Bauer and Gerrit Cole. Wheeler’s scouting report noted his mid-90s fastball, his potentially plus curveball, and his developing changeup. Despite that deep arsenal, Wheeler's transition to the big leagues was a bit rough. In 2013, he carried over the control problems that he had flashed in the minors, walking 4.14 batters per nine innings.
Thankfully, Wheeler has already started to improve. In 2014, Wheeler’s BB/9 fell slightly, to 3.84, and his improved control contributed to his impressive 9.08 K/9. Though his ERA rose, his FIP and xFIP both fell from the previous season's marks.
It's normal for pitching prospects to grow into their stuff. Zack Wheeler is only 24 years old. Take a look at the stats of his peers: Bauer has been through two organizations over three years and in his first full season, posted a 4.18 ERA and 4.01 FIP with 3.5 BB/9. Cole arrived with a bang in 2012, pitching to a 3.22 ERA and a 2.91 FIP, but in 2014, his ERA and FIP were both in line with Wheeler’s.
In his first two seasons with the Dodgers, Clayton Kershaw walked over four batters per nine innings, and it took Max Scherzer three years to see his BB/9 fall below three and his K/9 to settle above 9.2. In short, Wheeler is not unsual in his development; Harvey and deGrom are the anomalies.
How can Wheeler reach the next level?
Wheeler’s problem is not his stuff, but rather his control. The key to Wheeler improving is for him to simplify his arsenal. What do we all know about Wheeler? He throws high heat, and he has a solid curveball. He also struggles against lefties. Let’s take a look at some of his numbers from 2013 and 2014:
Wheeler is throwing five pitches, and his fastball, slider, and curveball have improved considerably. He's even throwing his sinker for more strikes. One pitch is very ineffective, though: his changeup. An earlier article on Amazin' Avenue noted that Wheeler would be better if he improved his changeup. While he has made some strides, his strike percentage on the pitch just doesn’t cut it; you can’t throw a pitch for strikes less than a quarter of the time and be effective.
Wheeler doesn’t trust his changeup because he can’t locate it. Effective changeups typically have around a 10-mph differential from the fastball (though there are some exceptions—like Felix Hernandez—to that rule). Wheeler’s changeup is typically only seven miles per hour slower than his fastball. More importantly, lefties, who are better at picking up the break, either lay off the pitch or crush it when it's throw over the plate. For what it’s worth, look at what left-handed hitters are doing against all of Wheeler’s offerings:
While Wheeler's curveball and slider have become considerable weapons, his changeup produced six strikeouts all season and a .170 ISO. As a point of comparison, Wheeler makes left-handed hitters look like Jonathan Lucroy or Freddie Freeman against his changeup. It’s time for Wheeler to scrap the pitch altogether.
Maybe Wheeler lacks control because he throws too many pitches and has to focus too much on his mechanics. It’s hard to be a five-pitch pitcher, let alone get plus-offerings on all of your off-speed pitches. His curveball is developing into a real weapon and his slider has been steadily improving since his call-up. His fastball is very impressive, even though batters know when it's coming. Imagine how much more effective that fastball would be if he mastered an out-pitch against lefties.
How would Wheeler pitch without a changeup?
There are many possible ways for Wheeler to adjust his approach without a changeup. For example, he could pitch more like Sonny Gray. Gray’s curveball is nasty—the eighth best in baseball last season (for reference, Wheeler’s was 30th, which is still very good). Gray crushes lefties with his curveball when he is behind in the count, and throws essentially no changeups:
Also, note Gray’s increased sinker usage when he is ahead of the count, and its drop when he is behind in the count. If Wheeler increases his curveball and sinker usage, it could help make his fastball even more of a weapon. Losing the changeup would help him focus on those other pitches.
In 2013, Rick Porcello actually developed a curveball specifically to induce ground balls and strike out lefties, and it’s worked: Following his first season sporting a curveball, Porcello’s ERA fell by nearly a point. He thought that his ineffectiveness against lefties may have been because his changeup and sinker were too similar. Now take a look at the horizontal movement and vertical movement of Wheeler’s changeup and sinker. They are nearly identical. Could Wheeler’s sinker get better if he dropped his changeup? Could he use the sinker as an out-pitch that gets ground balls?
Regardless, Wheeler should just drop the terrible changeup and focus on improving his curveball and sinker. Porcello’s curve slots in 12 places behind Wheeler’s on Fangraphs' effectiveness charts, and his sinker is only a bit better. These charts aren’t perfect, but they give us a glimpse into the how well different pitches work. Wheeler could use some added focus on his curveball and sinker to go along with his already developing slider—which, though a work in progress, is already better than Porcello’s. With a better slider and curveball—and a harder fastball—Wheeler could essentially become Rick Porcello, but with more strikeouts.