So often with prospects, you see the "Drew Pomeranz" analysis: this guy has two big league pitches and if he can add a third (or fourth) one he could be a solid big league starting pitcher, but if not his future is probably in the bullpen.
It’s hard to sustain success in the big leagues as a starting pitcher with just two pitches, something Pomeranz himself demonstrated early in his career. Only with the development of his changeup to complement the fastball/spike curve duo has the former A’s lefty emerged as a successful starting pitcher.
So it’s not surprising that Kendall Graveman’s emergence as a prospect coincided with the addition of a cutter. Graveman arrived in Oakland armed with four pitches: his signature sinker, the newly developed cutter, a changeup and a slider. Graveman rode that arsenal to inconsistent but promising results as a rookie (6-9. 4.05 ERA).
The breakdown of Graveman’s pitch selection? In 2015, he threw the sinker 55% of the time, the cutter 25%, his changeup 11.5%, and the slider 8.5%.
The start of 2016 was no different. In Graveman’s first start of the season he threw the sinker 59.5% of the time, then started throwing it less (46%, 39%, 42%, 39%) as he mixed in his secondary pitches more. In fact out of his first 12 starts only twice did he throw his sinker more than 50% of the time. He also was pitching very poorly.
On June 12th, at Cincinnati, Graveman threw only 38% sinkers, mixing in his cutter (38%), slider (16%), and changeup (9%) quite a bit. At the end of the day, his ERA for the season stood at an unpalatable 5.28.
Graveman’s next start was on June 17th against the Angels. You don’t see this often: his use of the sinker jumped from 38% in one start to a whopping 70% the next. Utilizing his sinker nearly twice as much as before, Graveman had a "breakout start" tossing 7 IP of 1 run ball on just 3 hits, walking only 1 while striking out 4.
Perhaps more significantly Graveman threw his cutter 23% of the time that day, meaning that he used his slider (4.4%) and changeup (2.2%) for only 6.6% of his offerings. The less he mixed it up, the less he turned to his slider and changeup, the better he pitched.
As it turned out, though, that was just the beginning. Let’s fast forward to Graveman’s best start of the season: his last one. At Houston on Saturday, Graveman threw 8 shutout innings on just 3 hits and 0 BBs (5 Ks) before running out of gas to begin the 9th. He was truly dominant.
Graveman’s pitch distribution on Saturday? 92.5% sinkers, 7.5% cutters.
That’s...You just don’t see that from a starting pitcher unless it’s R.A. Dickey throwing 92.5% knuckleballs and 7.5% "fastballs". Or Bartolo Colon, who is a freak of nature and thrives on being the exception who proves the rule. Graveman essentially became a one-pitch pitcher who just occasionally — and by occasionally I mean about every 13th pitch — mixed in one other pitch. And he was dominant, basically unhittable.
I will fascinated to watch two aspects of Graveman’s first start after the break. One, will he pick up where he left off and throw 90+% sinkers, a few cutters, and that’s it? And secondly will he be effective again, even dominant? It’s hard to imagine and yet easy to see on a spreadsheet: the less Graveman mixes it up, the better he pitches. Go figure.