If you’ve watched even a handful of Milwaukee Brewers games this season, you should know full well that the bullpen has been phenomenal. Despite losing All-Star closer Corey Knebel, Milwaukee’s relief corps hasn’t missed a beat - while missing plenty of bats.
With such a reliance now on bullpens in MLB, manager Craig Counsell has a huge advantage with the types of arms at his disposal, the early success they’ve shown, and how he has utilized them on a nightly basis. It’s the key recipe to the team’s 23-16 start.
The Crew’s relievers have done everything. They’ve shut down major rallies. They’ve stranded tons of runners. They’ve closed out tight games, won contests in doubt, and come in early to keep the Brewers in games - sometimes leading to a comeback victory (see Friday night in Colorado).
How have they continued to do this on a regular basis? As a group, they are absolutely dominating the strike zone and controlling at-bats. Denying contact and limiting easy bases have keyed their supremacy.
Heading into Saturday’s games, Milwaukee relievers lead the National League in strikeouts-per-nine-innings (K/9). The bullpen’s 10.30 K/9 has allowed them get out of jams, avoid too much bad luck, and shake the confidence of opposing batters.
Of course, the Brewers are led by Josh Hader’s historic left arm. He tops the NL with an insane 18.78 K/9 rate (minimum 20 innings pitched). Hader isn’t just doing this in one-inning stints. The southpaw has pitched at least two frames in eight of his 14 appearances. It hasn’t slowed him down.
In 11 of those 14 outings, Hader has fanned at least three hitters, with the highlight being an eight-strikeout performance on April 30th. Hader set an MLB record that night by punching out eight batters in just 2.2 innings in a 6-5 win. The 24-year-old fireballer was filthy, allowing only a walk among the nine men that came to the plate.
But Hader’s brilliance has been nearly matched by Jeremy Jeffress. In fact, in some ways, one could argue Jeffress has been more impressive. Jeffress ranks 18th in the NL in K/9 at 8.18 and has been a master at stranding inherited runners. Pitching with a certain swagger and confidence, Jeffress owns a minuscule 0.41 ERA.
Meanwhile, a handful of arms haven’t reached the 20 IP mark, but still have quality K/9 numbers. Taylor Williams sits at 14.54 K/9, with Corey Knebel at 13.50 in limited action. Brandon Woodruff, as a reliever, has posted an 11.12 mark thus far. Then you have Jacob Barnes at 9.0 and Brent Suter with an 8.10 K/9 out of the bullpen.
The stunning mix and amount of high strikeout rates are one of the main reasons Milwaukee’s bullpen has the highest collective WAR in the NL (2.6), the best xFIP (3.28), and the second-lowest ERA (2.61), trailing only the Arizona Diamondbacks.
But plenty of relief pitchers and staffs can rack up strikeouts - that is common with the current state of the game. What has been somewhat surprising and incredibly important for the bullpen has been its ability to avoid allowing free passes.
Milwaukee Brewers’ relievers own the second-lowest walks-per-nine-innings (BB/9) mark in the NL at 3.32 BB/9. Last season, the Brewers owned the highest BB/9 in all of baseball with their relievers at 4.26 BB/9. The turnaround of nearly one walk per inning less is enormous.
Not counting Adrian Houser or Hernan Perez, the Brewers have seven players with a BB/9 rate under 2.85 this year. Woodruff sits at 0.0 in a few innings, while Suter (1.35) and Knebel (1.93) sit under two. That leaves Matt Albers (2.04), Hader (2.35), Jeffress (2.45), and Dan Jennings all under 2.00 thus far.
Again, Hader has been the most ridiculous in this regard. Looking at just the raw strikeout and walk numbers for him is rather comical. In 23 innings, Hader has 48 strikeouts (tops among all relief pitchers) and just six walks. Others include: Jeffress (20 K, 6 BB), Williams (21 K, 9 BB), Woodruff (7 K, 0 BB) and Knebel (7 K, 1 BB).
Among this plate domination, there are two fascinating aspects to their ability to collect strikeouts while not getting crushed or give up walks.
For one, Milwaukee’s bullpen has thrown the 3rd-fewest percentage of first-pitch strikes in the NL, throwing a strike to open an at-bat 56.4% of the time. One would think the combination of high whiffs and low walks means you’re getting ahead a lot. Not so much.
The second interesting aspect to this is how good Brewers’ relievers have been as getting swings and misses at balls within the strike zone. They are the best in the league, getting a whiff on 20.1% of pitches in the zone. That is typically an indication of nasty “stuff” that hitters can’t handle.
It’s all the more interesting because Brewers relievers are just middle-of-the-road and getting swings and misses at pitches outside of the strike zone. Whatever the strategy and execution - it’s working.
This start to the season for the bullpen has been something to behold. The combo of arms and the consistent victories at the dish remains the fuel behind Milwaukee sitting seven games over .500 on May 12th.
There are some worried about burning out the bullpen with such high usage, and that is a fair concern. At the same time, Counsell has mostly been able to give his guys rest when needed, knowing another two or three arms have proven capable of getting outs - especially punch outs - while keeping men off the bases.
If they can remain on a similar path and be near the top of both K/9 and BB/9 this season, there is no reason Milwaukee wouldn’t be in the thick of a playoff hunt come late September.
Statistics courtesy of FanGraphs