Louis Head Joins an Under-the-Radar Marlins Bullpen

Unless you’re a diehard fan, you’d be hard pressed to name a single member of the Marlins bullpen. Given that they traded away a bunch of their relievers in July and still look like they’re a few years away from building a true contender, that’s not surprising. Building a lockdown relief corps isn’t the top priority based on where they are in their rebuild. But GM Kim Ng mentioned during last week’s General Manager Meetings that adding depth to the bullpen was part of the offseason to-do list — a bit of surprise given the context above. They started to address that depth right away, too, acquiring right-handed pitcher Louis Head on Sunday from the Rays for a player to be named later or cash considerations.

Miami’s relief corps was pretty solid in 2021, with the third best park- and league-adjusted FIP in the National League, 8% better than league average. But Marlins relievers weren’t exactly flamethrowers; collectively, they posted a 22.0% strikeout rate, the fourth-worst mark in baseball. Instead, the team employed a bunch of pitchers who ran above-average ground-ball rates, helping them successfully manage the contact they did allow. As a group, they had the fifth-highest ground-ball rate and second-lowest barrel rate in baseball.

Bass was signed to a two-year deal last offseason, making him the highest paid member of this group. A surprising number of minor league free agents ended up making a solid contribution in the majors, and the rest were acquired via the same kind of under-the-radar trade that brought Head into the fold. Despite all their success this year, the average age of these relievers is 30.3 years old. It’s a competent collection of relievers assembled from the castoffs of other organizations, and Head fits in perfectly.

After spending eight years in the minor leagues, Head made his major league debut in April at 31 years old. Originally drafted by Cleveland in the 18th round of the 2012 draft, he spent time with the Dodgers and Mariners before latching on with the Rays on a minor league deal in February. After sitting out the entire 2020 season, he was close to giving up on baseball, but Tampa Bay helped him turn everything around. “It’s kind of like a movie, really,” he told our David Laurila in early September. “I went from released to sales to playing in the big leagues.”

His first year in the majors wasn’t easy, either. The Rays took full advantage of his status as an optionable player, shuttling Head to and from Triple-A 12 separate times during the season. Despite the added stress of constantly moving to and from Durham, Head posted good numbers with Tampa Bay. In 27 appearances, including two starts as an opener, he struck out 23.9% of the batters he faced and walked just 6.7%. He also made 26 appearances in the minors, where his strikeout rate was a much more robust 32.2%.

The key to Head’s sudden success after toiling away in the minors for so long was a revamped slider. He goes in-depth into the development of that pitch and the impact it’s had on his repertoire in that interview with Laurila; it’s a really worthwhile read to see how he approaches his craft. The most pertinent point is this:

“Getting more horizontal break on [the slider], and less vertical break on it, has really just made a world of difference. It goes off the plane of my fastball better; hitters see fastball out of the hand. When it was more up-and-down, they were able to dive down and get it. Now when they try to dive down to get it, it’s going away from the barrel.”

Head’s slider used to be shaped more like a curveball, with more vertical break than horizontal. With the adjustments the Rays had him make to the pitch, he still gets that drop, but now he’s added a ton of sweeping action to the pitch, giving it elite movement in both directions.

The amount of vertical and horizontal movement he generates ranks in the 91st percentile for both characteristics among all sliders thrown at least 100 times. Here’s what it looks like in practice:

When he’s able to locate the pitch on the outside corner like that, right-handed hitters have a horrible time trying to make contact; he ran a 37.3% whiff rate against them with his slider in 2021. That’s a touch above league average, but not as high as you might expect from a pitch with such excellent physical characteristics. Perhaps the results lagged behind expectations because he had trouble locating his breaking ball in competitive areas. Over 40% of the sliders Head threw this year ended up in the chase or waste zone, more than 3 inches off the plate, and opposing batters swung at just 20% of those pitches. Earning a chase on those pitches is the goal, but too many of them were non-competitive and became easy takes for the batter.

With a completely new movement profile on his slider, Head likely struggled with his command of the pitch in 2021. The good news is that when batters did manage to make contact with the pitch, they barely mustered any sort of solid contact off it. He allowed just nine hits, two for extra-bases, and opposing batters produced a mere .271 xwOBA on contact off his breaking ball.

Despite all that work, the Rays’ 40-man roster crunch made Head expendable; he’s already heading into his age-32 season, and Tampa Bay’s pitching staff isn’t lacking depth. With the Marlins, he has an opportunity to stick in the majors on a more permanent basis. As he grows more comfortable with his revamped slider, he could see better returns with the pitch, giving him a higher ceiling than you might expect from a castoff.