The Red Sox offense has been extremely frustrating this year, as we all know at this point. That’s not the same as saying they’ve been bad, of course, because by the numbers they haven’t been. They are fourth in baseball in terms of runs scored and eighth in the game by wRC+. It seems hard to complain about that, and yet when you watch the games it often seems hard not to complain about them. Granted, they have been better recently and they do have guys like Xander Bogaerts and Rafael Devers, among others, who are putting up All-Star-caliber seasons. In fact, one could make the argument that this year’s lineup top-to-bottom is deeper than the one they sent out in 2018, albeit without the same kind of lethal top-end production.
There are a few reasons why they have seemingly been worse than the underlying numbers may indicate. Part of it is situational hitting and sequencing, as they have been more than capable of putting runners on base (they are fourth in OBP) but have struggled to come through with the big extra-base hits needed to put together extended rallies. That issue has been well-documented. The other issue has been a little less publicized (from what I can tell, though I could be wrong!). That is: They have been bad against left-handed pitching.
It’s a bit of a strange issue, because just looking on the roster on paper you’d think they’d be more than fine when southpaws are on the mound. This is a lineup, after all, that is led by Mookie Betts and J.D. Martinez and Bogaerts. Those are three of the best right-handed hitters in the American League. Even further down the lineup they have Christian Vázquez and Michael Chavis, among others.
Despite the presence of those hitters, Boston is in the bottom-third of the league in terms of performance against left-handed pitching. By wRC+, they rank 22nd in the league with a mark of 88, meaning they have been 12 percent worse than the league-average hitter when a lefty is on the mound for the opposition. There’s no one glaring issue as a team, but rather that they are average-at-best in every facet of hitting — strikeouts, walks, power, turning balls in play into hits — against southpaws. When you put that all together, you get struggles.
Looking a little bit deeper and breaking down the roster by their performance against lefties, there are three guys who stand out to me as the real key to the team’s issues against lefties and the key to turning it around. Those three would be Betts, Chavis and Eduardo Núñez. Martinez, Bogaerts and Vázquez, mentioned above, are doing what you want them to do against lefties. Martinez in particular has been stellar with a 222 wRC+. Lefties Andrew Benintendi and Rafael Devers have been below average, but not by any startling measure. In fact, Benintendi with a 94 wRC+ has actually been better than I thought. Jackie Bradley Jr. has been a disaster but, well, that’s kind of expected.
No, it’s the three guys mentioned here that are really killing the Red Sox. Betts, Chavis and Núñez are putting up a wRC+ of 58, 68 and 58, respectively, against lefties. We’ll start with Núñez, because his case is the most simple. The issue here is not with the player but rather with the manager, who keeps insisting on using him against lefties. It’s true that he is a righty and Brock Holt, the other second baseman on the roster, is a lefty. It’s also true that, generally speaking, the pitcher’s platoon split is more important than the hitter’s. That said, since the start of last year it’s become abundantly clear that Holt is a better overall hitter than Núñez. It’s also clear that Núñez has never been a guy to mash left-handed pitching. He has an 84 wRC+ against lefties in his career (93 against righties, for whatever that’s worth). Holt, meanwhile, has a 96 wRC+ in his career agianst lefties (92 against righties). One may counter with the fact that Holt has been bad (62 wRC+) against southpaws this year, but that would ignore that he’s only gotten nine plate appearances. The solution here is simple: Stop treating second base as a platoon and find other ways to get Núñez his playing time.
With Chavis and Betts, things are a bit more complicated. With these two, you have guys with a history of hitting left-handed pitching well. Last season, Betts had a 212 wRC+ against lefties. Chavis, meanwhile, has always been a bit better against righties but has more than held his own against southpaws in the minors. For the rookie, the issue comes down to plate discipline. When he makes contact he is hitting for power with a .241 Isolated Power. However, he is striking out in more than a third of his plate appearances against lefties while walking just over three percent of the time. That is an untenable ratio. Chavis’ problem appears to be that he can’t lay off the offspeed stuff. According to Brooks Baseball, the young righty is swinging at nearly three-quarters of changeups he sees from lefties and whiffing at over 40 percent. Similarly, he’s swinging at 60 percent of curveballs he’s seen and whiffing at the same rate. It’s a lot easier said than done, of course, but he needs to make an adjustment to lay off these offerings and get into hitter’s counts against lefties to see more fastballs.
For Betts, the issue is with balls in play. In terms of plate discipline he is doing just fine with a strikeout rate just over 12 percent and a walk rate over 13 percent. However, he has an Isolated Power under .100 and a batting average on balls in play under .250. That is not going to work. Lefties are actually throwing Betts more fastballs this year than in 2018, but he is not squaring them up. A big issue seems to be an adjustment made by defenses. Betts is always pull-happy, but he is being shifted a ton in these situations. Last year’s MVP is 12th in terms of plate appearances against the shifts for righties against left-handed pitching. Furthermore, among the 120 righties with at least ten PAs against the shift with a lefty on the mound, only 22 have a lower batting average in these situations. As with Chavis, making these adjustments is easier said than done but Betts needs to find a way to hit around the shift. Hopefully, that can spark a boost of confidence which can lead to the power we’re used to seeing from him against lefties.
The Red Sox seem to be trending in the right direction on offense, though they’ll be tested this week against the Twins. While they will only face right-handed starters in this series, there is plenty of talent on the left side with which they’ll have to contend if they want to be among the best in the American League once again. Guys like Blake Snell and James Paxton and CC Sabathia and J.A. Happ and Wade Miley, among others, provide frustrating looks from southpaws from some of the best in the American League. Fortunately, the Red Sox only need to turn around production from a few spots to get back to where they should be.