Rick Porcello’s repertoire is not working

The Red Sox are heading into this week’s All-Star break feeling relatively good about themselves. Granted, it’s impossible to outrun the overall disappointment of the first half of this 2019 season, but in the shorter term they got the job done. They took care of business against bad teams over the last week, winning five of six games. Even amid those wins, though, there were real issues that couldn’t be ignored. Specifically, the pitching was extremely worrisome throughout the run with the offense doing the heavy lifting to pick up these victories. That was fine against bad teams, but it’s clearly not a sustainable formula for winning.

We all know the issues with this bullpen, between the lack of top-end talent, the lack of depth and the overworking of, well, everyone. It’s not great! It’s also not the only pitching problem on the team. With all of the legitimate gripes about this ‘pen, it can be easy to overlook that the entire rotation is disappointing right now. Even David Price hasn’t quite been himself of late, though he’s the least of this pitching staff’s worries. As far as the most of the worries go, one could make a pretty good argument that title belongs to Rick Porcello.

The 2016 Cy Young winner did go on a nice little run from about mid-April through May, but on the whole this entire season has been rough for Porcello. He has made 18 starts on the year, averaging less than 5 ²⁄₃ innings per start, and has pitched to a 5.33 ERA with a 4.50 FIP and a 5.97 DRA. His strikeouts are down, his walks are up and he’s allowing a batting average on balls in play over .300. It’s not ideal, to be honest. The righty is also in the midst of a terrible stretch, pitching to a 12.75 ERA over his last three starts in which he’s allowed at least five runs in each outing. That, of course, includes the disaster in London when he allowed six runs while recording just one out.

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Porcello’s entire Red Sox career has been a rollercoaster, as we all know, and one of the driving forces of his success or lack thereof has been his repertoire. There’s little doubt that he became a totally different pitcher immediately upon coming to Boston, ditching his long-time heavy ground ball tendencies and becoming more and more of a flyball-oriented pitcher. Relatedly, he has stopped relying so heavily on his sinker and instead worked more in the upper-third of the zone with his four-seam fastball. The key has been finding the right balance between the two pitches. This year, the balance is off.

While the four-seam fastball has proven to be weapon for Porcello at times, it is not some sort of defining pitch on which he should ever be leaning. All of his seasons with the Red Sox have featured a higher four-seam usage rate than any season in Detroit, but the aforementioned Cy Young season in 2016 featured his lowest rate of usage of the pitch. This year, he’s using the four-seam more than any other season of his career, throwing the offering just under one-third of the time.

In some ways, the pitch has actually been more effective this year than in the past. While his walks are up on the year, his fastball is resulting in a called ball at a lower rate in 2019 compared to 2018. It’s also leading to significantly fewer home runs. However, it’s still hard to justify using this pitch so often. For one thing, the lack of home runs is unlikely to be sustained. He’s allowing slightly more fly balls with the pitch this year, and we all know about how the baseball is affecting the home run environment this year. On top of that, presumably at least part of the reason Porcello has thrown more fastballs with the Red Sox is to get more strikeouts and allow less contact. That hasn’t worked this year, with his whiff rate against the four-seamer down to 10 percent compared to 12 percent last year, 14 percent in 2017 and 15 percent in 2016.

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So, why is Porcello throwing so many fastballs this year? There are always multiple reasons for these things. His control has been shakier than usual this year, leading to more counts in which he’s fallen behind. That, in turn, leads to more fastballs to throw strikes. On top of that, though, Porcello has also not been able to turn to his changeup. While the offspeed pitch has never been a massive part of his arsenal, it is failing him in 2019. The changeup is being taken for a ball 44 percent of the time this year compared to 34 percent of the time in 2018. It’s also being hit for a home run at a far higher rate and getting fewer whiffs.

The biggest area in which you can see this effecting Porcello is against lefties. Obviously, the changeup is the main weapon for any pitcher against opposite-handed hitters, and the failure of the pitch is causing some major platoon splits this year. Lefties are hitting .287/.357/.489 on the year against Porcello for a .354 wOBA. (wOBA is on the same scale as OBP.) For context, a .354 wOBA is within a point of players like Bryce Harper’s and Gary Sánchez’s line for the season.

The Red Sox need their rotation to improve in the second half if they are going to make a run into the playoffs again in 2019. The bullpen needs to get better, too, but even with improvements it is still a supporting unit. The rotation is the focal point of this roster, and it needs to start acting like that. For Porcello specifically, that doesn’t mean he has to be an ace. He just needs to be a useful mid-rotation arm. If he’s going to get there, the answer is usual is with his repertoire. He needs to lean less heavily on his four-seam, turn to his sinker a bit more and most importantly find a way for his changeup to be a useful pitch again. If that doesn’t happen, not only will the Red Sox be in trouble for the second half but Porcello will also cost himself an awful lot of money in free agency next winter.

Pitch usage numbers come from Brooksbaseball.net