Justin Masterson shut out the Twins for 7.2 innings last night, allowing just four hits and no walks while striking out six, and remarkably did so while throwing fastballs on 103 of his 104 pitches. Seriously.
His timing was especially amusing because just a few hours earlier Sam Miller wrote a Baseball Prospectus column about all-fastball repertoires and wondered how long it would be before someone went with 100 percent heat in a start.
Masterson was damn close, throwing just one slider among 104 offerings, and Jordan Bastian of MLB.com (at the Twitter urging of an intrigued Miller) talked to the right-hander about why he bothered using the one non-fastball:
Well, you know, we thought we’d probably use it more. That one would hopefully kind of put it in the back of the head like, “Oh, later on in the innings, is he going to throw one here? Is he not?”
Along with that little intro to Game Theory he also said the approach was a case of “don’t change what’s working.” In other words, if the Twins kept showing that they couldn’t hit his fastball why did he need to throw anything else? Masterson got six strikeouts and 15 ground-ball outs while allowing zero extra-base hits, and only a Chris Perez blown save kept him from winning a 1-0 game while throwing one pitch slower than 90 miles per hour.
I’ve been skeptical of Masterson as a starter because I wondered if his lack of secondary pitches would eventually force a move to the bullpen, but that looks kind of silly right now. He has a 2.64 ERA and 101/40 K/BB ratio in 136 innings spread over 20 starts this season and, as Bastian notes, he’s thrown 82 percent fastballs.