The Miami Marlins made a bunch of moves this past offseason in order to bolster their infield, but the move they made last season before the trade deadline could turn out to be the most important for 2015. The Marlins felt they needed more starting pitching after losing Jose Fernandez for the year and witnessing the struggles of Nathan Eovaldi and Jacob Turner, at least in terms of ERA. The Fish then pulled the trigger on a cost-controlled, long-term asset in Houston Astros righty Jarred Cosart, a former top prospect who throws hard and had problems controlling his pitches. The Marlins got five seasons of team control of Cosart, but they paid a hefty price in the deal; they traded away top-100 prospect Colin Moran, former top prospect Jake Marisnick, and minor league fodder in order to acquire Cosart and the since-traded Enrique Hernandez.
"Kike" Hernandez was not given much of a chance on the roster, but Cosart started 10 games and threw 64 innings for the Marlins to good superficial results. He posted a 2.32 ERA and 3.32 FIP, dropped his walk rate slightly from his Houston days, and convinced the Marlins' brass that they had a contributor on their hands. The problem is that, just one year prior, Cosart was walking more hitters than he struck out, and the Marlins just gave up on two pitchers in Turner and Eovaldi who shared similar difficulties on the mound with strikeouts.
Cosart is by no means a guarantee to even come close to repeating his strong work with Miami at the end of 2014. So who will the Marlins get this season?
It was easy to like what Cosart was doing in Miami thanks to that shiny ERA. But a lot of what he was doing in Houston, he also did in Miami.
The big difference here was that he dropped his walk rate from 10 percent to 8.5 percent, a direct byproduct of attacking the zone a little bit more like most Marlins pitchers have been doing. Otherwise, the ERA and FIP drops were as a result of him allowing just two homers versus seven in his Houston days and him allowing a lower average on balls in play. Hitters batted .267 on balls in play against Cosart in Miami versus .302 in Houston. Say what you will Adeiny Hechavarria and his defense, but the Marlins' infield was not its defensive strong suit last year. Some amount of that success may have been good fortune for Cosart.
Meanwhile, the problems he has to fix are still question marks. The control was improved in Miami, though it remains to be seen if it will stick. The other issue is whether Cosart can find enough strikeouts to compensate for his merely average walk rate. Eovaldi and Henderson Alvarez got away with deflated strikeout rates in part because they were walking batters at a five or six percent rate. Cosart allows too many baserunners to not lean on the strikeout as much. His grounder rate is good, but not so good that he can rely on in to bail him out with double plays every time a baserunner reaches. Last season, Cosart stranded 78 percent of baserunners with Miami, but over the course of the year, he actually pitched worse with runners on base, with more walks and a lot fewer strikeouts than he posted with the bases empty.
The Optimist View
What does Cosart have to fix, and how can he go about doing this? Well, he has two routes upon which he can embark. The first is to emulate Alvarez and go the contact route, depending on your defense to help you prevent runs. Cosart already has some of the tricks to the trade, such as a grounder-inducing cutter as his primary fastball. The cutter is even thrown hard, much like Alvarez's unusual two-seam fastball.
The only problem is that Cosart has not dropped his walk rate significantly. With the Marlins, he posted a 52 percent rate of pitches in the strike zone. That mark would rank only ahead of Tom Koehler with the Fish's primary starters since 2013, and it would rank two percentage points behind Alvarez, Eovaldi, and Jose Fernandez. This does not mean that Cosart will be more effective at that level, but given that a similar groundball pitcher has done a decent job with that approach, it may be worth an attempt.
Could Cosart miss enough bats with that kind of zone rate? I would count on him to do so given the presence of a cutter-style pitch and a decent curveball as a secondary offering. Alvarez has lesser swing-and-miss stuff and relies on a changeup as his secondary pitch, which is less likely to work against same-handed hitters. If Cosart could reach the midway mark of his walk rate from last year and the walk rate Alvarez regularly posts, we would see a seven percent walk rate. Combine that with a modest improvement towards the ceiling of strike-pounding starters and you could see a 17 percent strikeout rate.
Is there a player who has a similar ratio of strikeouts and walks with ground ball rates above 50 percent? Two names came up when I looked for comparisons. Dallas Keuchel is projected for similar rates by Steamer for this upcoming year. Charlie Morton posted better ground ball rates but has nearly identical strikeout and walk marks. Those pitchers are worth between 1.5 to three wins, depending on their park factors. If Cosart can make these modest strides, we could easily see a league average starter or 2.5-win pitcher, much like we saw last year overall.
The Pessimist View
Of course, the pessimist view can go the other direction fairly quickly. Pitchers routinely post poor walk rates, though they rarely get a chance to show how bad they actually are. There are only nine starters since 2012 who posted a walk rate greater than 10 percent. However, one is a clear worst-case scenario for Cosart, as this pitcher also had poor strikeout rates and a high ground ball percentage. Former Astros starter Lucas Harrell got grounders on nearly 55 percent of his balls in play and had nearly identical strikeout and walk rates compared to Cosart's career marks thus far. He had a 4.85 ERA and 4.54 FIP in 359 2/3 innings and was worth 0.9 wins per 180 innings.
Similar pitchers have had issues like this with middling strikeout and walk rates. Joe Kelly threw 327 1/3 innings, had a nice 3.41 ERA but a worse 4.11 FIP and was worth just one win per 180 innings. Roberto Hernandez took ugly strikeout and walk rates and added on a terrible home run mark and was below replacement level for the last three years.
The clear downside for Cosart is that he continues to pitch like he has his entire career. That pitcher is a one-win guy, while the upside is that of perhaps a 2.5-win player. The Marlins stand to gain maybe 1.5 wins between the best and worst of Cosart. This is yet another big swing for an important player in 2015.