Jarred Cosart is coming off a funky debut, one that is going to convince more than one less-than-savvy owner to proclaim him a sleeper. The number that counts is 1.95. That was his ERA. 94.5 is another positive number associated with him. That was his average fastball velocity. Unfortunately, the rest of the data set is oozing the disgusting goop of an ugly regression ahead.
Cosart spent most of his time throwing a cut fastball and curve ball. He’ll mix in the occasional change-up as well, but it’s more of a show me pitch at this stage of his career. His cutter shows signs of being quite good, although we can’t draw any conclusions from PITCHf/x data alone. What we can say is that in 708 cut-fastballs, including 138 balls in play, batters have managed a tepid .077 ISO and .228 BABIP. That could be small sample noise, in fact it probably is, but there is a chance that his cutter is the kind that induces unusually weak contact. Purely for comparison, and let me be clear that this is like comparing an apple to a drawing of an apple, Mariano Rivera‘s cutter came packaged with a .078 ISO and .251 BABIP.
From his pitch usage, it’s obvious that the cutter is his bread and butter, but he’ll use his secondary pitches anytime he isn’t behind in the count. All of his pitches show low whiff rates adding up to a 5.7% swinging strike rate. That was the eighth worst rate among starters with 50 innings or more. He’s sandwiched between Scott Diamond and Ryan Vogelsong – not the most inspired company.
As previously referenced, Cosart comes preloaded with some ugly peripherals. He had the highest strand rate among all starters last year at nearly 86 percent. Yu Darvish was next highest at 84 percent. However, we can expect that sort of result from a pitcher who struck out one-third of the batters he faced. Cosart managed to strike out just 13 percent of batters. We can be reasonably sure that his .246 BABIP helped secure that high strand rate.
His cutter was the only pitch that saw BABIP “luck” and it’s possible that it will outperform the average fastball. However, even if we credit Cosart with the holy grail of cutters (I’m implausibly comparing Cosart to Mo again…), we should still expect at least three percent more hits on balls in play. If we treat Cosart as we do any other pitcher, we should expect his cutter to allow about seven percent more hits on balls in play.
There’s more – Cosart somehow achieved his 1.95 ERA while walking more batters than he struck out. And this isn’t like when Aaron Cook accomplished that feat by walking nobody and striking out less than nobody. Cosart handed out free bases to a full 14 percent of batters. He faced 135 batters with the bases empty and walked 26 (19.3%), but that rate improved to nine walks in 111 batters with runners on base (8.1%). I can’t tell you if that is signal or noise. I have some scouting reports criticizing the mechanics of his wind-up, but I’m inclined to believe that they are an after-the-fact rationalization.
Plate discipline data is also not favorable. He threw first pitch strikes eight percent less often than league average. Barely more than one-third of his pitches were in the strike zone. Nonetheless, batters still made a ton of contact including a 95 percent rate on pitches within the strike zone. Taken together, Cosart struggled to hit the strike zone so batters were patient. But when batters did swing, they hit him quite frequently.
Cosart does appear to have the inside track on a rotation job in Houston. The Astros rotation is headlined by Scott Feldman, Brad Peacock, Dallas Keuchel, and Lucas Harrell. Cosart is the front runner among the remaining options which include Paul Clemens, Brett Oberholtzer, Alex White, Asher Wojciechowski, and Anthony Bass. The Astros could conceivably acquire an additional veteran to forgo that thrilling rotation battle altogether.
As of today, the fifth spot appears to be Cosart’s to lose. The Astros will likely give him a chance to fail before making any changes since he’s a well regarded prospect. But his shallow repertoire and command issues make it seem like he could be better in the bullpen. If the cutter plays up a couple ticks and he can get his walk rate down to his minor league rates, he could be a good weapon out of the bullpen. If he can get his walk rate down to the eight percent rate he’s shown out of the stretch, he might have elite reliever upside. Remember, that could be purely noise too.
As a starter, I consider Cosart to be a potential very late round flier. To me, he’s a less attractive version of Joe Kelly, who I also consider as no better than late-round flier material. I’m most fascinated with Cosart in leagues that have cheap, long-term keeper mechanisms – like Ottoneu. His elite relief profile could pay out a year or two down the road, especially since the Astros need to eventually fill that position.