The Rays Way: Tampa Bay embraced a new slider-heavy pitching focus in 2019

Last week we checked out a couple of trends on the offensive side of things for the Rays in 2018, most notably that they traded in a lot of their power for a more contact-friendly (and speedy) approach at the plate.

This week, let’s take a trend on the run prevention side of things, namely the Rays pitch selection in 2018.

Kings of the Changeup

For a long time, the Rays dedication to the changeup was one of their main calling cards. James Shields was the leader on this front (24.1 percent career changeup rate; 34.1 percent his rookie season), but the Rays as a whole underwent the changeup revolution before the league as a whole began to notice how effective the pitch could be, part of that coming from the Rays diaspora moving around the league and spreading the good word.

The 2012 and 2013 Rays posted two of the three highest changeup rates (18.4 and 19.5, respectively) since the inception of Pitch F/X data allowed FanGraphs to start tracking these things in 2002 (only the 2005 Mets came in higher).

It wasn’t just Shields, either. They had Alex Cobb whose split-change defied true definition, Fernando Rodney who used the pitch to arguably add another decade onto his career, and remarkable regularity in the rotation. From top to bottom (Jeremy Hellickson, Matt Moore, David Price, et al.).

New Year, New You

However, the Rays seem to be making a change to their pitch type profile over the past two seasons. Here’s a chart of the rate at which Rays pitchers have thrown changeups as compared to sliders since 2002:

Look how massive the gap was from 2011-2013 and look at how quickly the two converge, with sliders taking the lead the past two seasons. The arc looks much the same if translated into MLB rank form, since we want to account for league-wide trends as well:

For a while, the Rays avoided sliders like the plague. The 2012 Rays threw sliders just 3.5 percent of the time, the lowest such rate since that aforementioned 2002 cutoff, and they did so by a decent margin. The 2011 and 2013 Rays also ranked among the bottom seven for slider usage since 2002.

Reason for Change

Part of this was likely due to the long-standing belief that sliders might be tied to Tommy John occurrence at a higher rate. Now that studies are seemingly showing that velocity is more likely to be a cause (and the Rays also had their highest average velocity ever in 2018, but that’s just the way of the league in 2018), the Rays are leaning into the slider game.

As our very own Ian Malinowski pointed out not all that long ago, there’s a decent chance that this change may be one of the overwhelming legacies that Chris Archer left on the Rays. As noted, this change has been building for a few seasons, and for several of those seasons, Archer was the leader of this cause.

Of course, some of what determines these types of trends is personnel. It’s worth noting, however, that the Rays leader in innings pitched in 2018 was Blake Snell, a pitcher who used his changeup (19.3 percent) more than twice as much as his slider (9.1 percent). While that would seem to make the case that they haven’t begun to favor the slider over the changeup, I think it actually improves the argument.

Things get a little wonky with the Rays when one uses starter/reliever splits due to the prevalence of The Opener, etc., but it’s worth noting that it was among relievers (21.4 percent) where the slider rate really pops. That makes it more likely that the team is indeed putting an emphasis on the pitch.

This overall change in strategy is not being powered simply by one pitcher, with the most innings, who embodies the new Rays Way. Rather, it is a bottom-up approach, with a higher percentage of the pitchers overall moving from changeup to slider.

Sergio Romo, Andrew Kittredge, and Chaz Roe all threw sliders in more than half of their overall pitches in 2018, and Diego Castillo wasn’t far off that pace (45.9 percent). Only Matt Andriese (who, importantly, was traded halfway through the season) came even close to using changeups at that sort of rate.

Then there’s Vidal Nuno. Nuno had a relatively balanced pitch mix before his move to the Rays before the 2018 season. See if you can spot the difference in his 2018 pitch mix:

Not hard, right.

As with all of these trends, they are more something to watch than something to solidly stake into the ground, but we’ll be monitoring whether the Great Slider Revolution continues in St. Petersburg next season.