Best rotation trio in baseball? Maybe

Burnes, Peralta, Woodruff have combined for sub-2.00 ERA

June 15th, 2021

The Brewers’ path to surviving the four-way National League Central scrap likely rests on the shoulders of three starting pitchers. But if they survive, those three are exactly what the rest of the NL doesn’t want to see in October.

Milwaukee is pushing through with a bottom-five offense across baseball, but the Brewers are neck-and-neck with the Cubs largely because of Corbin Burnes, Freddy Peralta and Brandon Woodruff. The trio of homegrown aces (Peralta was acquired as a prospect back in ‘15) flashed promise out of Milwaukee’s bullpen during its run to Game 7 of the ‘18 NLCS, combining for four earned runs allowed and 29 strikeouts in 17 1/3 innings against the mighty Dodgers offense. Three years later, the Crew’s front office is living a pitching development dream with three age-28 or younger aces.

As Peralta takes the ball Wednesday to begin this group's next turn through the rotation, he, Burnes and Woodruff have combined for a 1.93 ERA across 36 starts in 2021. The Elias Sports Bureau tells us that Milwaukee boasts the sixth trio of pitchers across the last 40 years to boast a 2.25 ERA or lower through their first 10 starts of a season.

A lot of starters have low ERAs this year, you’d correctly reply, but this group is even standing out among its peers. With Peralta’s 183 ERA+ representing the lowest mark of Milwaukee’s big three (100 = league average), the Brewers could be the first team to feature three starters that far above average (min. 150 innings) since ERA became an official stat in both leagues in 1913. Even if one accounts for regression and lowers the bar to a 150 ERA+, the Crew would be in rare company.

As fluky as those ERAs appear, anyone paying close attention in Milwaukee knows they’ve been well-earned. By FanGraphs’ FIP-based version of pitching wins above replacement, Burnes has been baseball’s second-most valuable arm behind Jacob deGrom, with Woodruff (tied for fifth) and Peralta (T-18th) also ranking among MLB’s top 20.

All three Crew starters are also among the top 10 starters in WHIP, largely because they don’t allow the luxury of contact. They’re all among the 15 best starters by FanGraphs’ K%+ metric, which, similar to ERA+, adjusts a pitcher’s strikeout rate in comparison with his peers and sets 100 as the league average. Burnes, Peralta and Woodruff could be the 12th trio of teammates since the mound was lowered in 1969 to boast strikeout rates at least 25% better than league average across at least 150 innings.

What about when batters are lucky enough to make contact? Nothing doing there, either -- all three Milwaukee aces are above average in hard-hit rate allowed. Blend together all those strikeouts and all that weak contact, and you have three of MLB’s 10 best starters by Statcast’s expected ERA. Again: there’s nothing fluky about this.

Best SPs by expected ERA, 2021
Min. 100 batted balls

Jacob deGrom (NYM): 1.29

2) Corbin Burnes (MIL): 1.50
3) Gerrit Cole (NYY): 2.37
4) Zack Wheeler (PHI): 2.41
5-T) Freddy Peralta (MIL): 2.51
5-T) Carlos Rodón (CWS): 2.51
7) Brandon Woodruff (MIL): 2.61
8) Tyler Glasnow (TB): 2.67
9-T) Yu Darvish (SD): 2.71
9-T) Max Scherzer (WSH): 2.71

Each of Milwaukee’s three stars took a different path to this point. Woodruff has had the smoothest ride, proving himself as one of baseball’s most productive starters since he slid into the Brewers’ rotation full-time in 2019 and featuring one of this year’s most dominant four-seam fastballs (.093 BA, .176 SLG, 49% strikeout rate). Burnes might be the most discussed turnaround story of 2021, thanks to his decision to ditch his four-seamer and attack with a filthy cutter/sinker/slider combo. And Peralta, who burst onto the scene in 2018 with a nearly exclusive four-seam approach, is no longer “Fastball Freddy” but a much more complete starter with quality secondary weapons in his slider and changeup.

With these three stacked back-to-back-to-back in the rotation, there’s been little relief for opposing lineups. Peralta’s streak of 11 straight starts with at least seven strikeouts was just snapped Thursday, and Burnes matched that run Saturday with an 11-start streak that’s still alive. Both are tied with Max Scherzer (2019) for the fourth-longest string of seven-punchout starts to begin a season.

Milwaukee’s rotation has also put up a combined nine starts of at least five innings with one or fewer runs and one or fewer hits allowed -- almost twice as many as other team. In fact, the 2021 Brewers have already tied the single-season Modern Era record for most dominant starts with that criteria.

Teams with most combined starts of 5+ IP, ≤ 1 R, ≤ 1 H
Since 1901
1-T) 2021 Brewers: 9
1-T) 2018 Braves: 9
1-T) 2018 Rays: 9
*No other team has more than five such starts combined in '21

It’s becoming clear that the Brewers’ rotation is the unit no team wants to face in October. Still, teams have to score in October, too, and the Crew might have to buck some recent history: The last World Series champion that featured three pitchers as its three most valuable regular-season contributors by WAR, per Baseball-Reference, was the 1995 Braves. Christian Yelich is starting to pick things up and Omar Narváez has been a pleasant surprise, but the Brewers still need more on offense.

If they get it? With these three arms in the rotation? Look out for Milwaukee.