The State of the Red Sox Bullpen

Almost all fans agree – the Red Sox should trade for a relief pitcher. As today’s Trade Deadline approaches, there is a very good chance this happens.

While this would be a smart addition to the squad, there are some Sox fans who think a new arm absolutely needs to be injected into an awful bullpen. This, however, is not true. In fact, the Red Sox have a really good bullpen this season. Let us take a deeper look into the individual statistics of the Red Sox relievers. This will hopefully establish exactly how the bullpen has performed this year. So, in the event that Dave Dombrowski doesn’t acquire a reliever, allow this article to reassure you that the bullpen is still fine (at least as of today), and has been one of the many strengths of the 2018 Boston Red Sox.

First, let me tell you something about myself: I love stats. Sabermetrics provide valuable information to help understand the game of baseball. It allows us to measure performances, as well as the ability to find hidden gems. There are numerous statistics that are useful when examining pitchers. However, at the risk of overwhelming you to death with numbers, I’ll just focus on three advanced stats that I believe are crucial for evaluating pitchers: DRA, WHIP, and wOBA against.

Statistical Background

For those of you not familiar with sabermetrics, allow me to briefly explain each one I’ll be using. Deserved Runs Average (DRA) is a stat developed by Baseball Prospectus and is meant to be an alternative to ERA; it aims to prove exactly how many runs a pitcher deserves to be charged with. DRA is measured on the same scale as Runs Allowed per 9 innings (RA/9); Beyond the Boxscore has found that RA/9 usually scores on average 0.30 higher per 9 innings than ERA. In English terms, you can judge DRA (and RA/9) similarly to ERA but expect results to be about 0.30 points higher (i.e. a “good” ERA score of 3.00 would roughly equal to a “good” DRA score of 3.30). You can find more details about it and the exact calculations that go into DRA here.

Walks plus Hits per Innings Pitched (WHIP) is a metric more commonly used in today’s game. Per FanGraphs, it is “essentially a measurement of how many base runners a pitcher allows per inning.” You can find more details and the exact context of WHIP scores here. Lastly, there is Weighted On-Base Average (wOBA). This is a stat that “combines all the different aspects of hitting into one metric, weighting each of them in proportion to their actual run value.” It is more accurate than OPS and is measured on the same scale as On-Base Percentage (OBP). Despite being used primarily for offence, wOBA can be helpful for evaluating pitchers as it shows the wOBA given up – it is the same scale but a lower wOBA score is better for pitchers. You can read further details and context about wOBA from FanGraphs here.

Evaluating the Pitchers

Craig Kimbrel: 2.05 DRA / 0.96 WHIP / .253 wOBA against

Matt Barnes: 2.16 DRA / 1.09 WHIP / .231 wOBA against

Tyler Thornburg: 3.18 DRA / 1.04 WHIP / .293 wOBA against

Heath Hembree: 2.94 DRA / 1.31 WHIP / .297 wOBA against

Ryan Brasier: 3.44 DRA / 0.90 WHIP / .198 wOBA against

Brandon Workman (demoted): 3.73 DRA / 1.02 WHIP / 2.92 wOBA against

Joe Kelly: 4.36 DRA / 1.25 WHIP / .277 wOBA against

Hector Velazquez: 5.25 DRA / 1.38 WHIP / .320 wOBA against

Brian Johnson: 5.50 DRA / 1.40 WHIP / .314 wOBA against

I’m a “bad news first” kind of guy, and the first thing that pops out to me is Hector Velazquez’s and Brian Johnson’s metrics. Their DRA scores are poor, their WHIP scores are below-average, and their wOBA against are the two worst among the relievers listed. I theorize Vazquez is still on the active roster due to his impressive ERA (2.45), but the advanced metrics show that he should have been demoted instead of Brandon Workman. In Brian Johnson’s case, the fact that he is the only lefty in the bullpen will likely keep him on the active roster. This is where the bad news ends. Kimbrel and Barnes score extremely well on these three metrics. There is an elite 1-2 punch in Boston. Factoring in all three statistics, Thornburg, Hembree, Brasier, and Workman all have overall great scores. We ought to be slightly wary due to Thornburg’s and Brasier’s small sample size (8.2 and 10.0 innings pitched respectively), but it’s starting to look like Thornburg is trending towards his elite class. Lastly, Joe Kelly, who is quite inconsistent, posts very average numbers. All in all, the Red Sox’ relievers have positive individual statistics so far this season.

Evaluating the Bullpen as a Whole

Now that we have looked at each pitcher’s stats, a look at the group’s statistics will further my point. Per FanGraphs’ leaderboards, the Boston Red Sox’ relievers have a collective WHIP of 1.23. That is 7th best in the MLB. The Red Sox’ bullpen also post a .289 wOBA against which is 3rd best in the majors. In terms of DRA, I was unable to separate the relievers from the starters; however, the team DRA is 3.83 which is 6th best in the MLB.

Conclusion

In conclusion, the Boston Red Sox’ bullpen is in a fine condition. In fact, it is one of the better ones in the entire league. That being said, trading for another reliever would be a wise move in my opinion. As the AL arms race continues, Houston and New York continue to build to their bullpens. Depth is always good during a playoff run and I hope that Dave Dombrowski finds a way to add a quality reliever. The AL is perhaps more competitive than ever and adding a big-name relief pitcher could go a long way in Boston’s efforts to separate themselves from the pack and win another World Series.

All stats courtesy of FanGraphs (https://www.fangraphs.com/) and Baseball Prospectus (https://legacy.baseballprospectus.com/sortable/)

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