We learn at a relatively young age that first impressions are incredibly important, and it’s something that sticks with you forever. In fact, I’d argue it’s one of the most vital lessons we learn. It’s just so important to be conscious of how you’re behaving the first time you meet someone. It is simply human nature to associate someone with how you felt about them when you first met, and it’s extremely difficult to deviate from that thought. Just ask Rick Porcello, who is still being referred to as a ground ball pitcher just because that’s who he was for the first part of his career.
Now that he’s entered the second stage of his career — his prime — it’s time we retire this “fact” about the righty. It’s no longer an accurate way to describe Porcello, and it hasn’t been since he came to Boston prior to the 2015 season. This might be obvious, but I still frequently hear people call him a ground ball-oriented pitcher. It also isn’t meant as a knock on the righty, of course, as he’s been doing just fine for himself. Despite no longer relying heavily on the ground ball, he’s coming off a season in which he won the Cy Young and is looking damn near as good this year outside of one horrendous night.
Generally speaking, we think of grounders as the preferred ball in play for pitchers, particularly in this day and age with the most complex defensive shifts we’ve ever seen. It’s impossible to allow a ball to go over the fence when it’s kept on the ground, after all. However, as long as fly balls stay in the park often enough, a fly ball-heavy approach can work just as well if not better, since fly balls that stay in the yard are harder to convert into hits than grounders. Porcello has been having a ton of success with fly balls.
If you look at Porcello’s batted ball data on Fangraphs, you’ll notice a clear trend over the last five years. Back in 2013, when he was still in Detroit, the former first round pick peaked in terms of inducing grounders. In that season, 55 percent of the batted balls against him were hit on the ground, the third-highest rate in all of baseball. The next season, his final in Detroit, that rate fell to 49 percent. In his first season in Boston, it continued to fall to just below 46 percent before getting down to 43 percent last year, when he won the Cy Young. We’re only seven starts into this season, but Porcello’s ground ball rate has continued to drop. Right now, just 39 percent of balls in play against him have been hit on the ground, a rate that puts him in the bottom-quarter of the league.
When dealing with samples as small as the early-season sample from this season is, there’s always a fear that one or two games can hugely skew the numbers. In fact, that is the case with Porcello’s ERA thanks to a drubbing from the Rays early in the year. That’s not the case with his ground balls, though. Of those seven starts, just two have included ground ball rates of 50 percent while the rest have seen rates below 40 percent. Looking back at last year, the results were similar. Of his 33 starts, just ten included at least half of the balls in play being hit on the ground, while 14 included ground ball rates under 40 percent.
The big reason for this, of course, is a change in approach from Porcello. His repertoire is a large part of that, and it’s something that’s been discussed in many places before. To summarize, he’s not relying nearly as heavily on his sinker as he did with Detroit, when he threw the pitch almost half of the time. Since coming to Boston, that usage is down below 40 percent, with more four-seamers and curveballs being thrown. In addition to the repertoire change, you’ll notice that Porcello is more willing to attack his opponents up in the zone. Obviously, this reduces the likelihood of ground balls, but it also increases the ability to get strikeouts. This season, Porcello is striking out over a batter per inning.
The image on the left (top image on mobile) shows Porcello’s zone plot from his Tigers career; the right shows his plot from his Red Sox career.
The fear that comes from allowing so many fly balls is that it will lead to a ton of home runs, and it’s a rational fear. In fact, he’s already allow eight home runs this season, giving him a horrendous rate of 1.67 home runs per nine innings. Of course, that is one of those instances where a small sample skews things, as half of the home runs were allowed in the one start against the Rays. Porcello is probably going to give up around one home run for every nine innings he pitches if he allows this rate of fly balls moving forward, which isn’t ideal but it will work fine for him. His batting average on balls in play should fall below .300 with this fly ball approach and the outfield defense behind him, and when you combine that with his impeccable control that means a lot of those home runs will be solo shots.
Porcello has turned himself into a consistently good pitcher, something some of us (read: me) weren’t expecting to see at any point. What’s even stranger is he’s done it while slowly changing who he is as a pitcher. It’s something that’s been happening for half a decade, and it’s time we finally come around and call Porcello what he is. He’s no longer a ground ball pitcher, he’s simply an outstanding pitcher.