Brewers Pitchers Are (Wisely) Resisting the League's Trend Toward Offspeed Stuff

The 2024 Brewers' innings puzzle has looked far different than in recent years. From a personnel standpoint, offseason departures and injuries have forced Pat Murphy’s squad to churn through an alarming number of arms one month into the season and rely heavily on relievers to compensate for short starts. The out-getting strategy also looks different on a per-pitch basis.

Brewers pitchers use fewer offspeed pitches (changeups, splitters, and forkballs) than any other staff in baseball, throwing them just 6.8% of the time. That’s a noticeable margin; the next-closest team is the Pittsburgh Pirates at 9.3%. The league average is 13.8%. Last season’s Brewers staff threw offspeed pitches 12.3% of the time. Milwaukee excels at maximizing pitchers’ strengths, and the flip side of that approach is limiting opponent exposure to weaknesses. That appears to be part of the story here.

The Brewers feature an assortment of pitchers with respectable fastballs, and they have one of baseball’s best defenses behind them. Many of these pitchers throw both sinkers and four-seam fastballs, enabling them to attack various parts of the strike zone with different goals, depending on the platoon matchup and game situation.

Coaxing weak or middling contact that the defense can convert into outs is a pillar of the Brewers’ run-prevention strategy, and throwing plenty of fastballs is the catalyst. Their 53.8% fastball usage rate is the fourth-highest in baseball, and their 26.7% sinker usage is the third-highest.

The strategy has been effective. Opponents have posted a below-average .380 slugging percentage in plate appearances ending on a fastball from Brewers pitchers, the ninth-lowest mark in baseball. Conversely, the Brewers lack effective offspeed pitches across their staff. That’s due to a combination of roster construction and their aforementioned plan of attack.

To break this down, let's begin with a crash course on offspeed pitches. Not all of them are created equally, and there can be differing driving forces behind their effectiveness.

The best changeups and splitters have noticeable, late fade and tail, because the pitcher excels at killing spin and pronating. These pitches often average around zero inches of induced vertical break. Because the ball is not fighting the effects of gravity, it drops more as it approaches the plate.

A more common changeup is the straight changeup, which relies mainly on separation from the fastball. It lacks inherent standout traits, but is effective because it looks like a fastball out of the hand.

Brewers pitchers average 6.7 inches of induced vertical break on offspeed pitches, the fourth-highest mark in baseball. That means their offspeed pitches typically behave as straight changeups. They don't profile well because they lack the separation from the fastball needed to make them effective.

The average offspeed pitch of a Brewers pitcher is 4.1 mph slower than their average fastball, the second-worst velocity differential in baseball. The Brewers also have the smallest difference between the induced vertical break of offspeed pitches and fastballs, at 5.1 inches.

That lack of shape differential stems mainly from the Brewers’ affinity for throwing sinkers, which can blend with changeups due to their similar movement profiles. Lackluster velocity separation and mediocre offspeed shapes create even more overlap. The pitch movement chart below illustrates this; notice how most of the changeups thrown by Brewers pitchers fall within the sinker clusters and often profile as worse versions of those sinkers.

According to the Stuff+ pitch grades available at FanGraphs, the Brewers have the worst changeups in baseball. The early results when their pitchers throw changeups are mixed: an above-average 35% whiff rate but a too-robust .407 opponent slugging percentage and a league-worst 23.3% chase rate.

The rest of the league is throwing more offspeed stuff than ever. It's no longer a fastball league, and after a few years of being a slider league, we're now seeing MLB become more of a generalized kitchen-sink outfit.

Knowing the strengths and weaknesses of their pitchers and the defense behind them, the Brewers have chosen which pitch types to emphasize and which ones to keep tucked away. Given the results so far, it appears they’ve made the right decision in throwing more fastballs at the expense of offspeed offerings, even if it's a move against the grain of pitching orthodoxy. With good conviction and command, a cutter and/or a sinker can be as effective against an opposite-handed batter as a changeup, and the Brewers' personnel right now make it worth pursuing that course.