Prior to being called up to Houston four starts ago, Jarred Cosart was a top pitching prospect. In fact, he has been ever since he was acquired from the Philadelphia Phillies in the Hunter Pence trade.
Cosart enjoyed a continued level of success all throughout his minor league career, and had a 3.29 ERA in 17 starts at Oklahoma City prior to making his major league debut. But no one could have expected Cosart’s debut would be as dominating as it has been so far in his four starts.
0.96 ERA in 28 innings over four starts.
Quite honestly, that just speaks for itself. As far as debuts go, it is a pretty impressive one. Cosart has averaged seven innings in his starts and his shortest outing was six innings. For a pitcher that throws as hard as Cosart does, you would want to see more than 11 strikeouts. The 23-year old’s fastball has averaged 95.3 miles per hour to go with a cutter that he throws at an average of 94.6 miles per hour (per Fangraphs), but he just has not shown the ability to finish hitters off. However, that clearly has not had a negative impact on his performance.
The other thing that you have to like about the start to Cosart’s career, is that he has managed to limit the baserunners. In his 28 innings, the starter has only allowed 30 total baserunners (18 hits and 12 walks), which is a huge reason why he held Tampa Bay scoreless for eight innings in his debut and only allowed one run in each of his three subsequent starts.
Not to rain on the Cosart parade, but there is some cause for concern here. As much as I would like to believe it, I just don’t think Cosart can keep up this level of success. Now I still think that he will continue to have success at the major league level this year and beyond, but it is highly unlikely he will be able to keep this pace up.
Specifically, there are two statistics that I would like draw attention to. Granted the sample size is small, but Cosart’s LOB% (Left on Base) and FIP (Fielder Independent Pitching) warrant a closer look.
In his brief career 86.4% of the baserunners Cosart has allowed have not scored. That is certainly a huge factor in why his ERA is the paltry 0.96 that it is, but you also cannot expect that rate to continue.
A growing majority of observers believe that FIP is a better measure of a pitcher’s performance than ERA. Without going too in depth, it is believed that a pitcher’s FIP is a clearer indicator of what you can expect his ERA to be. In Cosart’s case it is 3.54 which is still very strong.
I think everyone can agree that a regression is in order for Cosart and he has some growing to do. But all signs still point towards the rookie developing into a starting pitcher the Astros can count on going forward.