Why has Orioles CF Cedric Mullins struggled against lefty pitchers in 2022?

Orioles center fielder Cedric Mullins was a phenomenon in 2021, completing an arc that began with his demotion to AA Bowie in 2019 and ended with becoming the first player in franchise history to hit 30 home runs and steal 30 bases in the same season.

Mullins was rewarded for his efforts with an appearance in the All Star Game and his first Silver Slugger Award, but arguably the most impressive thing from his 2021 season was an accomplishment for which there is no award: the then-26-year-old abandoned switch hitting during Spring Training and began facing left handed pitchers as a left handed batter. In 224 at bats against left handed pitchers, Mullins managed a .277 average with 9 home runs and a .339 wOBA. He was a far more prolific slugger against righties, but becoming an above average hitter against lefty pitching almost overnight is an extraordinary achievement.

Mullins has remained an above average center fielder and one of the most valuable Orioles players, though has experienced slight regression offensively in 2022. A drop in power output is largely responsible, though debatably expected; his exit velocity hovers around the MLB average and was in the lower third of hitters last season in HardHit%. The other main culprit? Mullins’ numbers against southpaws have cratered.

Cedric Mullins versus lefties – A Tale of Two Seasons

When comparing Cedric Mullins’ expected stats in 2021 against LHP to the actual output, some regression was likely, but not a dropoff to the degree that’s occurred so far this season; Mullins would still be average against lefties if he was performing to his xWOBA in 2021 (.319). His 84.4 MPH average exit velocity this year is below league average, but not far off from the 85.9 MPH average in 2021, so what exactly has gone awry?

Singing the Batted Ball Blues

Despite similar average exit velocity, the rest of Cedric Mullins’ batted ball statistics against left handed pitching are a stark contrast from his breakout season. A .277 batting average has dropped to .208. Precipitous drops in SLG (152-point difference) and wOBA (83-point difference) have occurred, all likely due to a major shift in Mullins’ batted ball profile.

Major League batters have a .631 average when hitting line drives, which are defined as batted balls with a launch angle between 10 and 25 degrees, and the average hitter has a line drive rate in the neighborhood of 20%. Mullins line drive rate versus lefties has regressed from 21% last season to just 17.8%. Accompanying that is an alarming spike of fly balls of over ten percent and an even more worrying spike of infield fly balls, so much so that over a quarter of the batted balls against southpaws have been pop ups that don’t leave the infield. It will be nigh impossible for Mullins to hold his own against lefties if that infield fly ball rate doesn’t drop dramatically.

More sliders, more problems

Mullins’ struggles against LHP in 2022 are exemplified no better than when comparing his performance against sliders to a season ago. His .250 AVG, .307 wOBA, and run value of 7 against lefty sliders in 2021 have wilted to .107, .126, and -5 respectively. What in the world happened there?

Pitchers seem to have adjusted for one. Lefty pitchers have thrown Mullins sliders nearly nine percent more frequently (27.4% of the time) than last season (18.6%).

Secondly, while Mullins is actually hitting sliders from LHP harder on average than last year, the average launch angle of said batted balls has jumped from 13 to 23 degrees. Why is this important? Batted balls hit with a 23 degree launch angle with an exit velocity of 84 MPH (Mullins average EV) have a .255 batting average with only 9.8% resulting in extra base hits, none of which are home runs. The launch angle wouldn’t be as problematic if Mullins made harder contact, but right now a vast majority of his batted balls from left handed sliders are relative layups for defenders.

Can Cedric Mullins regain his form against left handed pitching?

It must be reiterated again: Cedric Mullins is still a really good baseball player who has only been facing left handed pitchers as a left handed batter for roughly a year and a half. While some of his numbers against them this year are concerning, it’s important to note that the sample size is still on the small side and if you combine his numbers vs. LHP from this and last season, it shows a .305 wOBA through 378 at bats – still impressive given the drastic change!

Left handed pitchers have adjusted to Mullins this season but given his track record, it’s entirely plausible that he adjusts to their adjustments and while maybe not being a perennial 30/30 threat, he will continue to be an above average center fielder for the Orioles for seasons to come.