Corey Knebel has been almost impossible to hit in September

With just under a week left in the regular season, the Brewers have locked up a spot in the postseason bracket, and looking securely locked in to the top wild card position in the National League. Carrying the load of this mass improvement has been their two biggest offseason acquisitions in Christian Yelich and Lorenzo Cain, both putting up “MVP” like seasons. While the starting pitching hasn’t been anything to write home about (the group is 17th in fWAR among the league), the bullpen has done tremendous work to get them here, playing a key part in the team playing above its actual Pythagorean level.

The Brewers bullpen seems be one of the more complete ones heading into October, holding the likes of Jeremy Jeffress, Josh Hader, Joakim Soria, Corbin Burnes, Xavier Cedeno, Jacob Barnes, and Dan Jennings. Getting some career-years to line up and sprinkling in some midseason acquisitions has made them one of the more improved bullpens since last year.

But while the bullpen has seen massive improvements, it hasn’t been smooth sailing the whole way. Their closer to open season was Corey Knebel who was coming off a career-best season in 2017 in which he was fourth among qualified relievers in fWAR. After allowing three earned run in his first three appearances of the season, he suffered a nasty hamstring injury (looked a lot worse than it was), which sidelined him for about a month.

He returned to the closer’s role for the Brewers in May, starting to look more like his 2017 self, posting a 2.25 ERA across 16 innings in May and June. Struggles would reappear in July though, as he would see a big decrease in strikeouts, helping contribute to a 5.25 ERA for the month. This would relegate him out of the closer’s role, where he would proceed to post an 8.64 ERA in his next 8 ¹⁄₃ innings.

Then on August 23rd, just over a year after representing the National League in the All-Star Game, he’d be optioned to Triple-A. The stay wouldn’t be long with September call ups just around the corner, as he only made one appearance at that level, but the demotion would be a representation of the fall he had over the past couple of months.

Now back in the Brewers bullpen, Knebel is pitching in a more versatile role, as Jeremy Jeffress now looks locked into the closer’s role and Joakim Soria and Josh Hader are getting most of the setup innings. Out of the 13 September appearances he’s made, he’s pitched in innings five, six, seven, eight, and nine, spanning from short one batter appearances to multi-inning stints.

So, how has Knebel handled this new role? Well, to keep it short, amazing. Here’s where some of his peripherals rank among 181 qualified relievers in the month of September.

• 0.00 ERA: T-1st
• 0.38 FIP: 3rd
• 1.50 xFIP: 4th
• 0.75 SIERA: 1st
• 55.3% K%: 2nd
• 48.9% K-BB%: 1st
• 17.1% SwStr%: 17th

Trying to get a better fell for this small sample size, the former first round pick looks like he’s pitching better than he ever has at the major league level.

A lot of Knebel’s improvement simply has to do with him refining his control. As it for many pitchers, getting ahead is important. This especially has held true for Knebel, as hitters are slashing a mere .138/.148/.276 this season when he’s ahead. But when batters are ahead, they slash .333/.533/.725 off of him. His .220 wOBA after an 0-1 count ranks in the top seventh of baseball. His .401 wOBA after a 1-0 count ranks in the bottom ninth. As you’d imagine, the difference between the first pitch of a plate appearance being a strike or a ball is huge, more so for him.

FanGraphs

The problems circled around him not doing that at an ideal rate throughout the season. But in September, his first-pitch strike percentage has surged.

This seems to ring off some adjustments he’s made to his release point, which is farther to right more than it ever has been the past two seasons.

If Knebel didn’t make improvements quickly, it was looking like there might not have been a spot for him on a postseason roster. Now looking like a lock, the 26-year-old figures to be another weapon in an already very deep Brewers bullpen.

Patrick Brennan loves to research pitchers and minor leaguers with data. You can find additional work of his at Royals Review and Royals Farm Report. You can also find him on Twitter @paintingcorner.