Drew Pomeranz only has two pitches. This is a problem — conventional wisdom states that a pitcher can only really be successful with at least three pitches, and it’s usually a pretty good idea to have more. It's become a sort of scouting shorthand: two pitches equals bullpen, three pitches equals rotation. Lately, however, a lot of pitchers with two pitches have been managing to stick and even do well in rotations. Even our own beloved Sonny Gray was essentially a two-pitch pitcher in 2013. There's some way to succeed here, some secret formula for success.

Pomeranz effectively no longer has a changeup

The A’s have created a sort of cottage industry out of teaching relatively unheralded two-pitch prospects changeups. Sonny Gray was drafted out of college without any semblance of a changeup, and the A’s coaching staff has assembled a legitimate out pitch out of thin air. Dan Straily, in an interview with Eno Sarris, said the A’s organization ran through 17 different grips with him before he found his changeup. The A’s have taken the opposite route with Pomeranz — he’s abandoned his changeup in his time with the A’s.

Pitch Fastball Curveball Changeup 2012 78.7% 14.4% 6.8% 2014 72.2% 26.8% 1.0%

He threw 9 changeups all year — it’s effectively gone from his repertoire. There’s a good reason for that: it’s junk. In 2012, according to Pitch F/X, it came in at 7.3 runs below average. If you have small children, don’t show them this next stat: hitters hit a whopping .563/.632/1.313 off of it.

Of course, Drew’s changeup is of the "slow, uncontrollable fastball" school of changeups. That school is not very well attended.

So the A’s obviously made a conscious decision that it was unsalvageable at some point. Conventional wisdom is that even a bad changeup is better than no changeup: you just need to keep it to keep like-handed batters off-balance. But this isn’t a death sentence or anything, there are absolutely successful two pitch pitchers in the world. The key is in finding a way to conquer the platoon split.

Who can survive in America (with two pitches)?

A quick sidenote here: Justin Masterson is by far the most successful two-pitch pitcher I can find Pitch F/X data on. He’s also the only pitcher I can find who only throws two pitches — every other example throws some sort of third pitch on occasion, even if it’s just 1% of the time like Pomeranz. Justin Masterson has evolved beyond that: he is 100% fastball/slider, which is really neat. The reason I’m not going to go into depth on him is that he’s entirely different from Pomeranz: he relies on his crazy power sinker, which is fairly unique.

Chris Archer was the most successful two-pitch pitcher of 2014, by a long shot. His fastball/slider mix is responsible for 94.8% of his pitches thrown in 2014 and produced a 3.33 ERA. Like Pomeranz, he throws a two-seam and four-seam fastball. Looking through their pitch distributions, however, I see one fairly obvious common weapon: the high fastball, particularly the high-and-tight fastball. Sean Doolittle would be proud.

Pomeranz goes down-and-in more often, but Chris Archer has a better two-seam fastball and typically uses it in that location. Tyson Ross uses this strategy too — despite living low in the zone typically, he is very, very fond of the high-and-tight four seam fastball. John Lackey, who has almost entirely phased out his changeup and curveball since 2013, is absolutely in love with the high-and-tight fastball. It's his bread and butter.

Here are some tendency maps for these pitchers' four-seamed fastballs to illustrate this point, thanks to the good people at baseballsavant.com. Pay special attention to how they use fastballs versus opposite-handed hitters (righties for Pomeranz, lefties for everyone else).

Drew Pomeranz

John Lackey

Chris Archer

Tyson Ross

Another way to conquer the platoon split is a good sinker. That’s Chris Archer’s bread and butter — on his way to finally figuring out left-handed hitters last year, he switched his main fastball from the four-seam to the two-seam variety. Pomeranz also throws a two-seamer, but not nearly on the level of Archer. I hesitate to say that it’s trash, given the fact that it has a promising amount of movement. But Pomeranz throws his five MPH slower than Archer’s (89 MPH versus 94.5 MPH) and seems to have no control over it.

Here are the results. Keep in mind that Pomeranz is the only lefty on the list, and typical wisdom would expect right-handed hitters to feast off of him whereas the others are trying to beat lefties.

Pitcher wOBA vs. LHP wOBA vs. RHP Pomeranz .300 .259 Archer .283 .307 Ross .289 .286 Lackey .316 .326

If the secret to success for two-pitch pitchers is abolishing the platoon split, it seems like Drew Pomeranz has managed to take his place among the stars.

All is not well, however.

However, there’s one major red flag in the data: Pomeranz’s batting average on balls in play. A low BABIP can be indicative of a pitcher having an excess of good luck, and Pomeranz’s BABIP versus righties is .231. Compare that to his fairly typical .297 BABIP versus lefties. BABIPs do not stay at .231, ever. Pomeranz’s crazy massive reverse platoon split is unfortunately not going to last.

There are a couple of indicators that the BABIP isn’t completely out of control. First of all, the high fastball Pomeranz employs so often against right-handed hitters leads to pop-ups. A massive 13.7% pop-up rate versus righties, to be exact. For context, that rate would have been #4 in the MLB last year. A high pop-up rate leads to a low BABIP — those pop-ups turn into outs almost every single time.

That high fastball also leads to a high flyball rate, and Pomeranz’s 36.0% would put him squarely in the top 35 qualified pitchers in that category. By the same logic, you’d expect flyball pitchers to have a low BABIP — home runs don’t count against BABIP, so Pomeranz is simply producing a lot of easy outs, especially in the generous confines of the massive Coliseum outfield.

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Drew Pomeranz is not going to maintain a 2.35 ERA in 2014. It’s simply not going to happen. But discounting him based on the number of pitches he throws and his subpar peripherals would be foolish. He won’t develop into an ace without a third pitch, it’s true, but I don’t think anyone ever expected that out of him. He’s keyed in on something that just might be one of the routes to success without a third pitch, though. Drew Pomeranz isn’t a mirage, he isn’t an illusion, and he isn’t a one season wonder. He’s a legitimate, feasible starting pitcher for a major league ball club. Isn’t that all we can ask?