What happened to Yovani Gallardo's Slider?

By Chris Kubak

2016 did not turn into the season that Yovani Gallardo or anybody else in Baltimore envisioned when the team took the field on Opening Day. After signing for 2 year/$22MM to help stabilize a shaky rotation for a potential playoff team, Gallardo proceeded to have the worst season of his Major League career. In other words, in 2016 he was mostly clobbered. Over the course of 118 unexceptional innings he scuffled his way to a record of 6-8, setting new career highs in ERA, batting average against (BAA), BB/9 inn, and HR/9 inn, and new career lows in K/BB ratio, and percentage of runners left on base. After all of this the Orioles were more than happy to send him packing, shipping him to the Mariners in a swap for outfielder Seth Smith.

So what went wrong this year? Was it an injury issue? While he spent some time on the DL during the first half of the year with a bout of shoulder tendinitis, the numbers show that he was not any more or less effective before or after the injury. Could you blame the cozy confines of Camden Yards for his diminished numbers? While he wasn’t great pitching at home, his numbers are actually much better in his 10 starts in Baltimore than in the 13 he pitched on the road…so that’s out. Nor can you really blame his move from the National League to the American League, since he demonstrated the ability to pitch in the junior circuit by putting up a solid (albeit nowhere near spectacular) 2.4 WAR with a 13-11 record and 3.42 ERA during his one season in Texas. So what is left? The answer may have to do with the fact that, to put it nicely, one of his most important weapons was not very potent in 2016.  

For a majority of his career, the slider has been an important part of Gallardo's repetoire. According to MLB Statcast Metrics, for the past six seasons his slider usage has been consistently around or above the 20% mark. During that stretch, he twirled over 750 of them every year from 2011-2015 (and threw more than that this year, depending on who’s data you are looking at). Where he used to mix his slider in fairly equal doses as his curveball, the curve has seemingly taken a backseat over the past two seasons. From 2009-2014 he threw his curveball about 20% of the time, but that number has dropped to 11% and 12% in 2015-16. At the same time his use of the slider has been on the rise, and he employed the slider at a career high level of 34% in 2016.  ​

You would think this shift in pitch selection would indicate that his slider has been more effective than his curveball, but the data actually suggests the opposite. From 2011-16 his curve has yielded a BAA between .206 and .235. By comparison, his slider has yielded diminishing returns and increasingly higher BAA’s for 5 years straight, which culminated in disaster this past season:

​Yes, that’s a .337 BAA against his slider…against a pitch that he threw 34% of the time! Perhaps just as startling, the SLG against his slider increased from .390 in 2015 to .577 in 2016 as well. So why did his slider break down so much last season? There is data that suggests that he has been leaving his slider further up in the strike zone than he did a few years ago. Similarly, his vertical and horizontal release point has seen some shifts over the past few years as well. While none of these provide a definitive explanations as to why his slider has lost its way, the trends are not pretty. If you develop a tendency to hang your slider out over the plate against lefties, hitters are going to try to sit on that pitch every at bat. Which quite possibly explain a good portion of Gallardo’s frustrations in 2016.  

The change in battery mates from the combination of Matt Wieters/Caleb Joseph/Francisco Pena to that of Mike Zunino/Carlos Ruiz has the potential to help improve Gallardo’s metrics a little, as does the move from Camden Yards to Safeco Field. But if I were the Gallardo, or for that matter the Mariners, I wouldn’t rely solely on those two things to lead to a reversal of fortunes in 2017. Whatever the causation is, Gallardo’s slider has lost a lot of its effectiveness over the last few seasons while he in turn continues to throw it more and more. It seems like it would be to his benefit to go back to the formula he demonstrated during the most effective stretch of his career (2010-2012). If his slider is going to continue to be a negative contributor to his arsenal, it would serve him well to rely on it less and lean more on his curveball instead.  

-Performance Data/Statistics were found via Fangraphs, MLB Statcast Metrics, and Brooks Baseball