The other area of regression for the Red Sox

As camp gets closer and closer, it’s about time we start thinking about what the 2018 Red Sox are actually going to look like even if there is so much more work left to do around the league this winter. When thinking about the upcoming season, I think the majority of us agree that there is going to be some positive regression for the offense even without considering an addition or two to the lineup. Between a new approach from a new coaching staff and players simply being better than they showed in 2017, it seems to be at least the majority opinion. There is certainly some disagreement as to the degree to which individual players improve at the plate and how much offense the team needs to add next year, but there is at least a base agreement that some improvement is on the way.

While that was the team’s biggest issue last year and the one aspect of the game that held them back through some many stretches of the season, improvement on that end doesn’t necessarily mean they are going to improve as a team. For one thing, other teams at the top of the league are improving as well. Plus, some positive regression could be outweighed by some good old fashioned negative regression on other parts of the roster. I don’t think the rotation will be much worse — or much better — than it was last year. I think the distribution of who is contributing what will certainly change, but the end result will be a similarly valuable rotation. The bullpen, though, is always a risk to change year-to-year. It’s the most volatile part of any roster in baseball, and it was also a massively important reason the Red Sox won the division in 2017.

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With all of the talk surrounding J.D. Martinez and other lineup targets this winter, it can be easy to forget just how good the Red Sox bullpen was last year. So, let’s get a little reminder. As a group, they posted a wildly impressive 3.15 ERA in 2017, a mark that was bested by only the Indians among all bullpens in baseball. They paired that mark with a 3.53 FIP which was third in baseball behind Cleveland and the Yankees. In short, this was one of the very best units in the game and it’s unclear whether or not they can be that good again.

Looking down the depth chart, there is reason to expect they should be very good again. Craig Kimbrel is still their closer, and he is still one of the very best relievers in all of baseball. That being said, he was otherworldly in 2017, and there’s a chance he regresses to being just elite in 2018. Carson Smith and Tyler Thornburg could be the keys, as they represent possibilities to be consistent set-up men that the team lacked last year. They have more upside than any non-Kimbrel reliever showed last year, although they are also big unknowns. Matt Barnes and Joe Kelly have their warts, but they also showed more good than bad last year. All in all, there is a wide range of possibilities with this unit, but that can be said of any relief corps.

Taking stock of the Red Sox’ starting pitching depth

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There is one area in which I can safely say the Red Sox bullpen is going to suffer through regression, though. That would be extra inning performance. This probably doesn’t seem like a huge deal because so few games go into extra games. However, this team’s performance in these games last year was absolutely one of the things that put them over the top against the Yankees in the American League East. Honestly, this team was a juggernaut in free baseball, winning 15 of 18 extra inning games. I can promise you it wasn’t because of the late-game offense, either. Instead, the bullpen hung tough through many late nights. Red Sox pitchers allowed just eight runs in 57 ²⁄₃ innings of work in extras for an ERA of 1.25. They allowed a tOPS+ of 41 in extra innings, which means they were a whopping 59 percent better in extra innings than they were normally. That is the 23rd lowest tOPS+ in extra innings since 1990. All of this is to say that the Red Sox relievers are probably going to be worse in extra innings next year.

At the end of the day, this isn’t a post that is meant to cause mass panic among Red Sox fans. Overall, I think the bullpen should probably be slightly worse than it was last year, but the improvement at the plate should more than make up for that. Where they will get much worse, though, is in extra inning games. Those 15 wins were crucial in a competitive American League, and finding that kind of edge will be crucial once again in 2018. Obviously, we’d all prefer they just make up for those wins with nine-inning games, but chances are they are going to be on the wrong side of a few more coin flips in 2018 compared to 2017.