The chatter around the internet of late is that, off his most recent stretch of dominance for Double-A Binghamton, Mets top prospect Zack Wheeler is ready for Triple-A.
So is he? Let's take a look.
Wheeler's stuff has looked great all season long. Scouts have praised his two plus offerings while dropping a "future no. 1" on the 22-year-old righty. Eastern League hitters have agreed, batting a paltry .169 against Wheeler, the best mark in the league from its sixth youngest pitcher. But stuff has never been the issue.
Wheeler's biggest weakness throughout his professional career has been his so-so command. Like most prep pitchers with such dynamic stuff, Wheeler battled walks as well as high pitch counts and the resulting early hooks that came with them. So let's take a look at how he's doing on both fronts in 2012.
First, let's look at the walks. In 2010, his first professional season, along with a sterling 10+ K/9, Wheeler posted a less sterling 5.83 BB/9 over about 60 IP for the Giants' Low-A Augusta affiliate. Wheeler wasn't much better in 2011, as he maintained the high strikeout rate but still walked batters at a 4.81 clip in Hi-A before he was traded to the Mets. He did improve in Port St. Lucie, however, over a six-start sample after he joined the Mets' organization.
That brings us to 2012.
We all know Wheeler has been a beast in Binghamton with a 1.88 ERA. Despite 30 K's in 25+ IP and an ERA of 1.75 in April, he was still sporting a BB/9 of 5. It was certainly understandable in his first exposure to Double-A hitters, but it was not the kind of incremental growth those hoping to watch Wheeler reach Triple-A this season wanted to see.
Fortunately, things changed in May. Wheeler began throwing more strikes, but opposing batters still hit 50 points lower against him (.141). In four May starts he posted those same 30 strikeouts but a much improved 2.33 BB/9, the best mark of any single month in his career.
Naturally, this improvement lent itself to longer outings. Though as Matt Harvey is learning this year, fewer walks and pitch efficiency are not the same thing. Learning to be economical with pitches, consistently getting ahead and working deeper into games are typically the skill set that pitching prospects develop last, often at the major league level. Fortunately, Wheeler has made strong gains in this area so far.
The following is a representation of Wheeler's pitch efficiency -- specifically, Overall Strike Percentage (K%) and First Pitch Strike Percentage (1st%) -- throughout his nine starts this season (click to embiggen):
In the month of April, Wheeler averaged 59% strikes thrown per game and just 56% of batters got a first pitch strike versus 68% and 71%, respectively, in May. Additionally, from April to May Wheeler has gone from averaging 21 batters faced per game up to 25.25. The average length of start has increased from just over 5 innings pitched to 6.75. In short, he's becoming a lot more efficient.
So on the surface one can probably surmise that based on the tremendous gains Wheeler has made over the last month, coupled with his tremendous raw stuff, he's probably ready for his next test. Now in the spirit of being conservative — as one should typically be when dealing with pitching prospects — it's fair to say that May is still only one month, so why not let him repeat that success over the course of June before discussing any possible promotion?
Conversely, there's an argument to be made that Wheeler is no longer really being tested by Double-A hitters. As one of the uncommon cases of a young pitcher with true superstar potential, it might be more beneficial for him to continue to sharpen these skills while plying his trade against the next tier of professional hitting. But that assumes Triple-A hitters will fare better.
Either way It's a judgment call, one which Sandy Alderson and his staff are no doubt discussing with every passing start. Yet the true beauty of the situation is that there really is no wrong decision. Wheeler has excelled so thoroughly at such a young age that nearly any outcome short of a start in Queens is justifiable. And at this rate, even that last part may be up for debate come September.