Is A Sophomore Slump Even Possible For Jose Fernandez?

Feb 18, 2014; Jupiter, FL, USA; Miami Marlins starting pitcher Jose Fernandez (16) gets a high five in spring training action at Roger Dean Stadium Mandatory Credit: Brad Barr-USA TODAY Sports

Recently there has been some wondering out loud going on (or on Twitter and the Marlins blogoshpere, anyway) about the possibility of Jose Fernandez going through a sophomore slump.  The talk reminded me of a post I wrote last year before the season discussing how Fernandez would fare in 2013 based on the stats other 20 year olds had put up in their first big league seasons.  I limited my comparison to just pitchers who had made their debuts since 2000, but the list still had some pretty impressive names including Clayton Kershaw, Zack Greinke and C.C. Sabathia.  Of course, it also contained names like Rick Porcello and Jeremy Bonderman.

To address the possibility of a sophomore slump for Jose, I thought it might be interesting to see how the 20 year olds did in their next big league seasons.  However, after the season Fernandez had in 2013 comparing him to Bonderman is just not going to cut it.  I needed to up the ante, so instead let’s use data on 20 year old or younger pitchers who had below 3.00 ERAs in a full big league season.  There have been just 14 such seasons since 1920 and only 7 since the mound was lowered in 1969.  I will limit things to those 6 pitchers (Dwight Gooden did it twice) since 1969 to keep things manageable.  Here are the stats for those 6 seasons:

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As you would expect, this is some pretty elite company Fernandez is keeping.  The list includes 2 eventual Hall of Famers and 3 eventual Cy Young Award winners.  Gooden and Valenzuela, like Fernandez, would win the Rookie of the Year award in the season listed here.

So here’s what happened to each of these guys the following year:

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Three of the five followed up the first season with another outstanding year.  Gooden was other worldly in 1985 going on to win the Cy Young Award that season.  Valenzuela and Blyleven were also very good as evidenced by their 122 and 119 ERA+ marks, respectively.  Eckersley would be a league average pitcher from an ERA+ standpoint in 1976, despite actually improving his K/9, BB/9 and HR/9 rates from the previous year.  Gullet fell apart, somewhat, posting the only losing season of his career, though it should be noted that his season was interrupted by a bout with hepatitis.

We already knew Jose Fernandez’s 2013 season was one for the ages, but this list just adds more fuel to that fire.  Beyond 2014, this history tells us that Fernandez is likely on a path to be one of the best pitchers of his generation.  As far as what the data tells us regarding a sophomore slump, let’s break it down this way – 20% chance to win the Cy Young, 40% chance to be an All Star, 20% chance to be just an average pitcher and 20% chance to get injured and tank.  Sure a sohpmore slump is possible, but the Marlins have to feel pretty good about the chances of Jose staying in the top 2 categories with an All Star appearance being a worst case scenario.