One Big Question: Can Nathan Eovaldi get his cutter back?

Welcome to Over the Monster’s One Big Question series. For those unfamiliar, this is something of a season roster preview where over the next 40(ish) (week)days we’ll be taking a look at each player on the 40-man roster prior to the season. If changes are made to the roster between now and Opening Day, we’ll cover the newly added players. Rather than previewing what to expect in a general sense, the goal of this series is to find one singular question — sometimes specific, other times more general — for each player heading into the coming season. We’ll go alphabetically one by one straight down the roster, and you can catch up with the series here. Today, we cover Nathan Eovaldi.

The Question: Can Nathan Eovaldi’s cutter be a weapon again?

After trading away Mookie Betts and David Price, there is very little doubt the 2020 Red Sox are worse than they would have been with those two. The question isn’t whether or not they are worse, but rather how much worse and, more importantly, how close to a playoff spot are they still? There’s no way to answer that with any sort of certainty — PECOTA gives them a 28.5 percent chance, for what that’s worth — but in my view the Red Sox’ chances are going to come down to whether or not the rotation can perform at or somewhere close to its peak.

The rotation, even despite not even really having a fifth starter as of this writing, can be solid 1-4, but there is a ton of variance with all four of those guys. Among them, Nathan Eovaldi could be the most important, and at the very least could have the widest margin of outcomes.

It seems like, at this point, a lot of Red Sox fans have given up on Eovaldi after what was, admittedly, a disaster last season. There are a good number of fans who would like to see him out of the rotation altogether and try to reclaim some value in a bullpen role. I’m not there yet myself, and while I get the sense I’m higher on his chances of a bounce-back than many, it’s hard to argue with the reasoning of most everyone else. That said, given the construction of the roster — like I said, they don’t even have a legitimate fifth starter right now — the Red Sox have little choice but to give Eovaldi another chance to start, and this is his chance to show that there is something there. If he’s going to do it, it would seem to all come down to whether or not he can get his cutter back.

Photo by Billie Weiss/Boston Red Sox/Getty Images

Any sense of optimism around Eovaldi has to go back to his 2018 season. That is obviously (and rightfully) going to be most remembered for his postseason run, but he was damn good in the regular season as well, both with the Rays and after the mid-season trade to Boston. Over that entire season he pitched to a 3.81 ERA with a 3.63 FIP and a 3.23 DRA. That wasn’t all that long ago!

Then, of course, last season was a major step back. He battled injuries and ultimately ended up shifting to the bullpen for the end of the year. In all, he pitched to a 5.99 ERA, a 5.93 FIP and a 6.37 DRA. He was worse across the board, but really it was the walk rate that stood out the most. After pounding the zone with great success the year before with a walk rate below five percent, Eovaldi came back in 2019 with a rate over 11 percent, the highest of his career outside of a 34-inning stint back in 2011, his first taste of the majors. He also saw a big increase in homers, though who didn’t?

All of that ties back to the cutter as well, though. This was the reason for optimism heading into last season, if you had some. It can always be tough to buy such a stark breakout from any player, particularly a pitcher like Eovaldi who already had established a mediocre track record. When that happens, you are looking for a tangible reason for such a change, and in this case it was the cutter. The righty had abandoned the pitch back during his time with the Yankees, but the Rays helped him bring it back and it turned him into a new man.

It was a huge weapon in that 2018 season. According to Baseball Savant, his whiff rate on the offering was 17 percent, which wasn’t huge but it was solid for a guy like Eovaldi who doesn’t rely a ton on missed bats. More telling was the average exit velocity of 88 mph along with an expected wOBA of .309 and an actual wOBA of .316. He threw it nearly as much as his four-seam, and it led to huge numbers.

Then, in 2019 everything fell off. Eovaldi was throwing it a little harder (a half mile-per-hour, to be exact), but his whiff rate fell to 12 percent, the average exit velocity off the pitch jumped to 92.3 mph and the expected and actual wOBAs were up to .425 and .433. It went from being a game-changing weapon to a liability, and as such he started leaning more on a four-seam that, while high in velocity, isn’t that hard for major-league hitters to crush.

It’s hard not to look at the cutter and see that it was the biggest reason for his massive jump in walk rate, too. According to Brooks Baseball, just under 26 percent of his cutters were called balls in 2018. Last season, that number jumped up to just over 40 percent. You’ll also see below on a few zone plots courtesy of Baseball Savant that Eovaldi was both missing more often off the plate to his glove side, particularly down, and getting fewer swings on those pitches. The glove side is, of course, the side of the plate where his cutter is most often going to end up. It should go without saying that if you are both missing the plate and not getting swings on those misses, you are going to walk a lot of players.

That’s pretty much the beginning, middle and end of those issues. Eovaldi couldn’t locate the cutter as much — you can also compare contour maps on this page for further comparison — and that made everything worse. As I said above, that led to more four-seam fastballs, which were crushed for home runs 1.4 percent of the time, which is a small number on its own but massive compared to the 0.4 percent from the year before. Again, part of that is just that the ball was flying out of every park, but it’s also that batters could more comfortably sit on the high-velocity but mostly flat pitch.

It’s clear not only from 2019 but really from his whole career that he needs his cutter to work, and work well. The best year, by far, he’s had in his career was the only year the pitch was a real weapon. I don’t know if his elbow injury made it harder for him to spin the pitch or if he was just feeling some pressure to get going after the injury slowed the start of his season and he tried overthrowing the pitch. It’s worth noting the slight jump in velocity as well as the increased frequency of misses to his glove side could support the latter. Whatever the issue, though, it needs to be fixed. The Red Sox need at least average production from their rotation this year, and Eovaldi is their number three starter. He needs to be at least pretty good, and he can’t even be that without a functioning cutter.