The Miami Marlins were expecting more from Jarred Cosart in 2015 after acquiring him the previous year for a hefty cost. His second half with the Marlins was surprisingly effective despite middling peripheral numbers in 2014, but that did not translate well in 2015. Cosart was saddled with problems with vertigo that held him back all year, and when he did pitch, he was awful, throwing too many walks and adding home runs to his stint of problems.
So the Fish are not confident that Cosart will assuredly win his rotation spot back, opening up the competition for the fourth and fifth spots among a slew of back-of-the-rotation contenders. However, Cosart had the most cost invested in him; acquiring five years of the former top-100 prospect cost Miami 2013 first-round pick Colin Moran along with Jake Marisnick. He will get the most opportunities to win the spot, and I suspect if Miami sees him decently healthy, he will get every opportunity to hold the position of fourth starter.
Starting Pitcher Depth Chart
Cosart faces some adversity heading into 2016. Health is part of the question, especially after an incident during a Spring Training start left him hobbling and questioning a knee concern. But after being a hyped prospect, he has struggled all throughout his career. He owns a career difference between his strikeout and walk rates of 4.1 percent, meaning he is barely striking out more hitters than he walks. Since 1993, 66 out of 543 qualifying starting pitchers have had career percentage differences between strikeout and walk rates at or below 4.1 percent. Only three of those pitchers put up career ERAs better than league average, and only one of those guys (Aaron Cook) threw during the most modern era. Cook also pitched in Coors Field primarily, which makes him a difficult comparison point.
Cosart, in other words, is in uncharted territory among pitchers looking to maintain decent numbers; his career ERA stands at eight percent better than league average despite his terrible strikeout and walk numbers. He holds one advantage; he has a mid-90's fastball with heavy sink that apparently can induce good ground ball rates, as he owns a career 54.6 percent grounder rate. Of course, Cook made a career out of a 57.5 percent ground ball rate and similarly terrible strikeout numbers, but Aaron Cook is a unique pitcher in baseball lore, and Cosart would be wise to try and do something more traditional for success, because replicating Aaron Cook is a hard task to ask of a man.
Source: Kim Klement, USA TODAY Sports
So can Cosart improve his game for 2016? When he pitched for the Marlins in 2014, he was hitting the strike zone more consistently than he did in Houston. He worked in the zone nearly 52 percent of the time, which was higher than his rate of 45 to 46 percent in 2013 and 2014 in Houston. That helped him put up the best half-year he ever threw up, with improved walk rates below 10 percent without losing his paltry strikeout rate. For a guy who struggles with walks and has a ground-balling sinker, maybe his path to success is to pound the strike zone much like other former Marlins. It would not be terribly difficult to believe that Cosart's problems with vertigo played a role in his 45 percent zone rate from last season.
However, the problem with this is that he had issues with this before the vertigo problems, and he only spent 64 innings of his young career pitching effectively. Meanwhile, his secondary stuff has still been ineffective at getting strikeouts or staying effectively in the strike zone in support of his contact-driven fastball.
Despite the potential problems lying ahead for Cosart, the projections show at least a passable pitcher in 2016. If he were projected to throw 180 innings, the value projected by ZiPS would put him at 1.5 wins for the 2016 season. This is by no means fantastic, but it is also more than almost any pitcher the Marlins threw out last season.
The reason for this confidence is a continued expectation that he will repress home runs. Marlins Park is a huge stadium and Cosart primarily gets ground balls, so there is definitely reason to suspect he will hold down homers. Last season might have been a location-based aberration, and he could return to a homer rate closer to his career mark of 1.7 percent.
The systems are also expecting some overall improvement in his strikeout rate, with the expectation that he at least gets up to around 16 percent after a career mark of 15 percent. This kind of regression towards the league mean may not be in store for Cosart, who may simply lack the stuff or command to get strikeouts. However, at least his age (26 years old for the 2016 season) could point to some improvement.
Overall, the three systems are expecting an average ERA of 4.14. At that kind of performance over 160 innings, the Marlins may get a 1.5-win season or a bit less out of Cosart. If they could coax that kind of performance out of someone with such baggage, Miami should be happy about Cosart's value at his current level of development. The hope is that he finds another gear and deduces a way to either become a true control-oriented ground baller or find the right mix to induce strikeouts. At this stage, it is difficult to predict this happening, but there may still be a small chance. The 2016 season may be the make-or-break campaign for Cosart.