Josh Collmenter of the Arizona Diamondbacks is the talk of the National League after delivering another scoreless outing against the Pirates on Thursday, in which he lowered his ERA to 1.12. Opposing hitters have had trouble against Collmenter's unorthodox delivery where his arm comes straight over the top. This arm angle strengthens his below-average fastball, which averages 86.8 mph.
Scouts consider his changeup as his only pitch that is an okay major-league-level pitch. Smoke and mirrors will only get him so far if he continues to pitch in the rotation every five days. Collmenter's strikeout rate is below average (5.59 K/9), and I have a hard time believing he will continue to post a 1.30 BB/9. He had a walk rate of 3.07 BB/9 in the 515 innings of his minor league career.
Collmenter continues to benefit from a .174 BABIP, a 6.5 percent HR/FB ratio and an 88.8 percent strand rate. His 3.64 xFIP, which is above average, indicates that a regression is more than likely. Other clubs in the National League might see through Collmenter's ruse after multiple looks. The start came against the Rockies on May 24 when he allowed five runs (two earned) on five hits and two walks in 4.1 innings pitched. Not coincidentally, the Rockies are the only team Collmenter has faced twice during the season.
I think Collmenter can have a decent future in the Diamondbacks' bullpen if he can face a limited number of hitters during an appearance. He lacks an average third pitch (he has yet to record a swinging strike with his curveball), which will get him in trouble down the road. He has a decent swinging strike percentage of 7.8, and his change-up is an effective weapon (swinging strike percentage of 13).
The Diamondbacks could be able to get three above-average seasons from Collmenter out of the bullpen, but it is foolish to think he can continue this success for six innings at a time every five days. Hideki Okajima proved that pitching artifices only get a pitcher with below-average stuff so far.