The Miami Marlins pitching staff is certainly outperforming expectations. While everyone knew Jose Fernandez is a beast, top prospects Nathan Eovaldi and Henderson Alvarez have blossomed into legit Major League starters. While all three entered the Majors with an appropriate amount of hype, fellow starter Tom Koehler did not. And for good reason.
Koehler, set to turn 28 in June, had been toiling in the minors since 2008 when he was drafted in the 18th round of the amateur draft. While he showed some glimmers of promise at times, he also showed a propensity to give up an insurmountable amount of baserunners.
In his first professional action in 2008, Koehler posted a 1.44 WHIP of 66 innings in Low-A. The following season, he improved somewhat to a reasonable 1.29. After showing significant improvement in 2010, as he posted his career-best 1.17 WHIP, he regressed once again, posting a 1.48 WHIP in 2011 and a 1.42 WHIP in 2012. He had allowed 12 walks over his first 23 innings before being called up to the Majors last season where he posted a 1.36 WHIP in 23 starts.
The WHIP is the most important thing to look at here because while some starters pitch to contact and others walk a lot of batters, Koehler has made a habit of giving up a ton of hits and walks. As such, his ERA has seldom been good.
He posted a 4.97 ERA in his first season in Triple-A, followed by a 4.17 ERA in 2012. Last season in the Majors, he posted a 4.41 ERA.
Now, suddenly Koehler finds himself as the Marlins’ best pitcher outside of Fernandez, sporting a 1.99 ERA after tossing eight shutout innings against the Mets on Wednesday. He also owns a 0.99 WHIP and 29 strikeouts to 17 walks.
Now, most pitchers with those numbers would be in line for a healthy amount of regression but Koehler in particular is not the type of pitcher to limit hits the way he has been. It doesn’t hurt that he has now faced the Mets twice (27th in hits), Atlanta (24th in hits), and San Diego (29th in hits).
His walk rate remains quite high at 3.9 and nothing in his past has suggested that he can limit hits anywhere near his current six hits per nine innings rate. Even in his best season in the minors he allowed eight hits per nine innings.
Once the hit rate returns to its more usual 8.6-9.0 rate, the ERA will return to its usual 4.00+. Unlike most pitchers with sub-2.00 ERAs, Koehler may be a bit harder to trade given his low 5.8 strikeouts per nine rate (exactly the same as it was last season) but some owner is going to be willing to bite and the 27-year-old sophomore is never going to have the fantasy value he does right now.
