Let's talk about a pitcher! He pitched for the Tigers and did so pretty well, but it always seemed like he had another gear he hadn't reached yet. In 2014, the Tigers traded him to a team in the AL East, and this pitcher immediately changed his approach with an increased focus on hard pitches at the top of the strike zone. His results changed soon afterward.
About whom are we talking? Because you read Beyond the Box Score, and are therefore very smart, and because I gave the answer away in the title, you know we're actually talking about two pitchers: Rick Porcello and Drew Smyly. They might not strike you as logical comps for each other at first, since their current situations aren't very similar. Smyly is of course on the DL, and their results have moved in opposite directions since their respective trades:
|Pre-trade RA9||Pre-trade FIP||Post-trade RA9||Post-trade FIP|
But as I'll show, the changes in process they underwent after leaving the Tigers were very similar. Is there something that might explain their drastically different results and what they'll be like going forward?
Back in September of last year, Jeff Sullivan wrote about Smyly's shift at FanGraphs. That piece was prompted by a Ken Rosenthal article that said the Rays had encouraged Smyly to elevate his fastball more frequently, particularly when trying to close out a two-strike count. Jeff found that Smyly had indeed been elevating much more and was converting many more strikeouts. On the other hand, Porcello's struggles this season have been well-documented in the charming Boston media and often connected to his increasingly elevated fastball. At least on the surface, it sounds like they made similar changes -- I know I've idly wondered if the Red Sox front office saw Smyly's improvement and tried to pull off the same thing with Porcello. As it turns out, that sense of similarity holds up to a more rigorous look as well.
I'm going to present some stats and heat maps below, for both pitchers, from before and after their trades. For Porcello, that's 2014 and 2015, and for Smyly, that's through July 31st of 2014 and the remainder of 2014 plus 2015. The heat maps have Porcello on top, Smyly on the bottom, pre-trade on the left, and post-trade on the right. Some stats come from FanGraphs, and the heat maps and the rest of the stats come from BaseballSavant.
|Elevated Pitch Rate||32.9%||40.1%||31.4%||38.8%|
|Hard Pitches w/ Two Strikes||54.7%||65.8%||55.0%||61.5%|
|Fly Ball Rate||29.0%||36.0%||41.7%||47.4%|
The changes the two pitchers went through are remarkably similar. Both began elevating much more frequently, particularly their hard pitches, and particularly with two strikes. The high fastball has been something of a sabermetric fascination lately, so this could've provided a confirmation of the theory that this specific combination of location and pitch type was particularly effective. Instead, things are even more confusing, with Smyly improving seemingly overnight and Porcello imploding just as quickly.
First, there's always the possibility that this is just randomness, and it's important to acknowledge that. Home run rates are notoriously volatile, and since the long ball has been the main reason Porcello has seen his RA9 and FIP balloon, it's plausible that he'll snap back to his historic home run rates and be what the Red Sox wanted him to be. Smyly's 1.96 ERA with the Rays in 2014 and 2015 is almost certainly less reflective of his true talent than his 3.37 FIP, and his sudden improvement has come in only 64.1 innings. That said, Dan Szymborski's ZiPS projection system thinks both pitchers will perform differently than their 2014 Tigers performance for the rest of 2015 -- for Smyly, a 3.53 FIP compared to a 4.03 with Detroit, and for Porcello, a 3.88 FIP compared to a 3.67 -- so let's assume there's something about Porcello that made the high heat strategy not work and something about Smyly that did.
The first thing that springs out from the above table, showing their pre- and post-trade stats side by side, is that while they both increased their K rate, Smyly both started at a higher K rate (20.0% vs. 15.4%) and increased by a larger amount (7.5% vs. 2.9%). To give some context, league average K rate thus far in 2015 is 20.1 percent; restricting that to starters, the average is 19.2 percent. Smyly was already running an average to above-average K rate, and the increased strikeouts from elevating pushed him into elite territory for a starter. Porcello, however, was a quality-of-contact guy, running instead an above-average ground ball rate and a below-average K rate. Increased strikeouts are obviously good, but it seems that a pitcher like Porcello stands to gain less in K rate from elevating fastballs and benefit less from that gain.
The flip side of Porcello's profile is that he historically has not allowed many fly balls (29.0 percent with the Tigers in 2014) compared to Smyly (41.7 percent pre-trade). More high fastballs leads to increased strikeouts, but it also leads to increased fly balls. For Smyly, this was a change, but it wasn't a major change -- he went from a pitcher with a high fly ball rate to a pitcher with a higher fly ball rate (47.4 percent with the Rays). Porcello, however, went from a ground ball pitcher who didn't need to strike out many batters to a fly ball pitcher who did (36.0 percent FBs with Boston), without the increased K rate to make up for it.
I'm not comfortable drawing any grand conclusions, however, because if there was an easy answer, I assume the Red Sox and Rick Porcello would have already found it and pursued it, and I wouldn't be writing this article. That said, I think it's very likely that Porcello's changed approach is partially responsible for his decline in results. Based on the differences between him and Smyly, I believe that, as a general rule, the pitchers who stand to benefit most from elevating their fastballs are those who already have a good K rate and will move into elite territory with a substantial bump, while ground ball pitchers face too many negative side effects for the positive K rate movement to outweigh.
Again, the fact that Porcello hasn't just gone back to his groundballing ways suggests that there's more to his decline than merely a decision to throw more high fastballs. I think both he and the Red Sox would welcome a sub-4 RA9/FIP and 2ish WAR per year, and if he could decide to go back to that, he would have already. But the curiously similar and divergent cases of Drew Smyly and Rick Porcello offer a glimpse into the potential effects of a conscious decision to throw a higher fastball and might help predict what pitchers a similar change would benefit and what pitchers it would harm.
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Henry Druschel is a Contributor at Beyond the Box Score. You can follow him on Twitter at @henrydruschel.