MLB Bettor’s Notebook: Breaking Down Best & Worst Bullpens In Baseball
Todd Kirkland/Getty Images. Pictured: Kenley Jansen.
Each week during the MLB season, Action Network’s Anthony Dabbundo will compile a weekly notebook of observations, analytical findings and actionable information to help bettors find an edge in betting the daily grind of a 162-game season.
The first month of the MLB season featured dominant bullpens and the death of the late-inning comeback.
Hitters have warmed up and caught up to the pitching from the shortened spring. The ball has started to fly more in warmer temperatures, and the league has seen an increase in bullpen meltdowns and late rallies recently.
There are few losses that are more frustrating as a bettor than the ninth-inning meltdown. However, bullpens are becoming more and more a part of betting baseball, as starting pitchers are not going as deep into games as they used to.
The five best bullpens by ERA are as follows:
- Houston Astros, 2.75
- New York Yankees, 2.84
- Tampa Bay Rays, 3.06
- Baltimore Orioles, 3.06
- Atlanta Braves, 3.08
Four of these five teams would make the playoffs if the season ended today, with the exception being Baltimore. Three of them also play in the AL East, with the Yankees leading the league in comeback victories in part because the bullpen has kept games close enough to enable them.
And here are the five worst bullpens by ERA to this point in the season:
- Cincinnati Reds, 5.24
- Colorado Rockies, 4.72
- Kansas City Royals, 4.71
- Chicago Cubs, 4.61
- Washington Nationals, 4.50
All five of these teams are well under .500, and none have a realistic chance of making a run to the playoffs in the second half of the season.
But much like I often write about buying low and selling high on certain pitchers, the same can be true for bullpens for the remainder of the 2022 season.
Buy Low on Cubs’ Bullpen
One of the biggest buy-lows in the whole sport right now is the Chicago Cubs’ bullpen. They rank 27th in bullpen ERA, but the bullpen sits fourth in K-BB%, which has proven to be one of the most predictive pitching metrics that exist.
The Cubs’ relievers have excellent stuff, ranking fourth in strikeout rate while getting remarkably unlucky with BABIP. Chicago ranks second-worst in bullpen BABIP and 24th in strand rate.
The Cubs might be selling pieces off at the trade deadline in the next month, which could make the bullpen worse and change the outlook. But for now, with the return of David Robertson to high-leverage situations as the closer, there’s reason for optimism.
Based on Eno Sarris‘ model from The Athletic, Robertson, Rowan Wick and Scott Effross all own above-average Pitching+ metrics. And Mychal Givens has above-average stuff despite mediocre command numbers.
Chicago’s biggest problem as a bullpen has been allowing too many homers. The group is the worst in the league in HR/9, but given a well above-average 15% HR/FB rate, you would expect that to regress positively and decrease in the coming months.
As the ball stays in the yard more, the Cubs’ bullpen should tighten up and keep down opposing offenses.
Sell High on Orioles’ Bullpen
As much as I’ve loved backing the Orioles this season and do have optimism for the arms at the back end of the bullpen, there’s some regression coming for Baltimore’s bullpen.
Jorge Lopez and Felix Bautista are both live arms with excellent stuff and good strikeout numbers. But this is not one of the five best bullpens in baseball when you look across the metrics.
It starts with K-BB%, and Baltimore sits 21st behind the Phillies, White Sox and Rangers, none of whom have good bullpens this year. Baltimore’s bullpen is also middle-of-the-pack in barrel rate and hard-hit rate. The reason for the improvement in ERA is down to two things: HR/FB rate and strand rate.
Some of that is the home park. Camden Yards went from a big-time hitters’ park to one of the biggest pitchers’ parks this season. The park holds more fly balls, but still Baltimore is top-seven in both strand rate and HR rate despite ranking 25th in strikeout percentage.
Baltimore should still be an above-average bullpen, but they’re not top five. Regression is coming, and don’t be surprised if the O’s start to squander some leads in the coming weeks.
Lopez and Bautista are excellent, but beyond them, the depth arms have been pretty fortunate to have deflated ERAs.
Which Bullpens Will Be Best Moving Forward?
A simple ranking of K-BB% would suggest which bullpens will perform the best for future games, and it projects really well for Atlanta to make another big second-half run and compete for a National League title again.
The Braves have the best K-BB% of all bullpens in baseball and may even look to improve further at the deadline. Atlanta hasn’t gotten consistent closer performances from new signee Kenley Jansen, who posted a two-run blown save on Sunday night against the Dodgers.
Right behind Atlanta are its NLCS foes from the last two seasons, with the Dodgers in second. As much as Los Angeles has seen its pitching depth tested, the bullpen remains stellar going forward.
Best Bullpens by K-BB%
- Atlanta Braves, 20%
- Los Angeles Dodgers, 18.9%
- Seattle Mariners, 18.2%
- Chicago Cubs, 17.5%
- New York Mets, 17.4%
You’ll notice that Atlanta is the only bullpen of the five that also finds itself in the top five based on ERA.
The Astros and the Yankees both have some regression coming with runners on base. They’ve been unsustainably good at getting out of jams, and that’s made up for their good but not elite strikeout-to-walk ratios.
The Mariners’ bullpen ran really well last year and has actually been a bit unfortunate with injuries and variance in 2022. Seattle is an excellent bet to improve, especially when you consider that Paul Sewald, Penn Murfee, Andres Munoz and Erik Swanson all grade out as elite bullpen arms by Sarris’ Pitching+ model.
The Mets might actually have the best bullpen in the Big Apple when looking at their underlying numbers and the increasing injury issues for the Yankees.
Worst Bullpens by K-BB%
- Kansas City Royals, 8.6%
- Arizona Diamondbacks, 10.3%
- Colorado Rockies, 10.6%
- Oakland Athletics, 11.1%
- St. Louis Cardinals, 11.5%
The Cardinals play excellent defense and often defy the regression metrics because of that.
But this bullpen just isn’t very good outside of the dominant Ryan Helsley this season. They have a bottom-10 rank in xFIP, strikeout rate and SIERA. Yet, they’ve maintained an average bullpen.
Because the starting rotation doesn’t go deep into games and lacks consistent back-end arms, you also have to be concerned about fatigue for St. Louis’ top arms (Helsley, Giovanny Gallegos, Genesis Cabrera).
The Cardinals are an excellent sell-high bullpen, and it should be noted that the Giants — who pitch to a ton of ground balls — and Cardinals are the only two teams in the bottom 10 of the bullpen K-BB% ratings that have a chance at the playoffs.
Based off of this deep dive into bullpens, I’m recommending a bet on Atlanta to win the NL East at +200.
There’s a sizable gap between the Braves and Mets, but they still have 15 games remaining with NYM. Charlie Morton is back to being himself, and the Braves have the better bullpen and a comparable lineup.