Hand up, if you had asked me over the last few years about Tanner Houck, I had major concerns about his ability to be anything more than a #5 starter at the big league level. It had been years of watching him try to develop a consistent third pitch that allowed him to work through a lineup more than two times and retire lefties regularly. Now, he’s a front-runner for the AL Cy Young and has a chance to start the 2024 All-Star Game, which is a crucial development for an organization starving to develop a homegrown ace.
Through 13 starts this season, there hasn’t been a more valuable pitcher in baseball than Houck, who leads all arms with a 2.9 fWAR. He’s simply shoving to the tune of a 1.91 ERA/2.21 FIP that includes an elite groundball rate of 54.5%. Despite not striking out a ton of batters with an 8.9 K/9, he’s become a master of keeping the ball on the ground, rarely walking guys with a 1.6 BB/9, and avoiding barrels at an elite clip of 3.9%.
This has been a major win for the new Red Sox pitching infrastructure, which has its fingerprints all over the 2024 version Houck. It’s impressive to see what type of development is possible with pitching gurus like Craig Breslow, Andrew Bailey, Justin Willard, and Kyle Boddy now implementing their philosophies into the organization. But Houck’s progress starts with the changes made to his splitter, with the pitch now featuring a completely new movement profile and usage rate.
In 2023, Hocuk’s splitter was thrown 11.4% of the time with 34.6 inches of drop and 13.6 inches of horizontal movement. It was used mostly against lefties and it was absolutely teed off on with a .310 BAA and .452 SLG. For anyone watching, it was clear that Houck wasn’t confident in the pitch and who could blame him, especially when the proof was in the pudding whenever he tried to work deep into a game.
BOSTON, MASSACHUSETTS – APRIL 17: Tanner Houck #89 of the Boston Red Sox gets ready to pitch the ball during the eighth inning of a game against the Cleveland Guardians at Fenway Park on April 17, 2024 in Boston, Massachusetts. (Photo by Jaiden Tripi/Getty Images)
Now, it’s been completely reshaped across the board, with him utilizing it 24.2% of the time and it becoming a weapon against hitters who swing it from either side of the plate. He’s added 3.7 inches of vertical drop to the pitch and has lessened its horizontal movement by 0.6 inches, giving it this diving effect that’s hard for hitters to square up. That’s led to a weak.183 BAA and .247 SLG so far in 2024, which is a complete game-changer compared to a year ago.
The changes don’t stop there for Houck either, as he’s completely eliminated his 4-seam fastball. While he only threw it 9.9% of the time last year, hitters were licking their chops whenever they saw it, as they posted a .325 batting average against it with a horrendous .550 SLG. Bailey has emphasized his arms focusing on throwing their best stuff instead of featuring a ton of different looks, and 2023 Houck wasn’t doing that.
Speaking of Houck’s biggest weapons, that puts the focus on his slider and sinker. While his sinker is largely the same from a movement and usage standpoint, that hasn’t been the case with his esteemed slider. He’s throwing it more than ever in 2024 at 41.9%, which is a few ticks up from last year’s mark of 38.4%.
In terms of movement, Houck’s slider still has almost exactly the same amount of vertical break, but it’s breaking harder from right to left than ever. He’s added 5.9 inches of horizontal sweep, which has made him a Pitching Ninja favorite every single time he takes the mound. Bad news for the competition, who are batting a measly .171 against it with a pathetic .220 SLG.
So, just to keep track of all the changes made by the Red Sox pitching infrastructure, the splitter and slider have both been transformed and the 4-seamer has been erased entirely. Lastly, there’s his cutter, which isn’t featured a ton at 3.2% in 2024 after being used 10.2% of the time in 2023.
BOSTON, MASSACHUSETTS – APRIL 17: Reese McGuire #3 of the Boston Red Sox, left, dumps water on Tanner Houck #89 of the Boston Red Sox after throwing a complete game against the Cleveland Guardians at Fenway Park on April 17, 2024 in Boston, Massachusetts. (Photo by Jaiden Tripi/Getty Images)
Houck hasn’t even been using the pitch on a regular basis this season, with him not throwing a single one in his last 3 starts. He did feature a few against the Rays on May 20th, but that was after facing them in his previous start as well, when he threw none. Prior to that was his May 3rd start against the Twins, so it seems like it’s no longer a significant part of his arsenal, especially with him leaning into the splitter more and more.
The result of all this growth has led to Houck leading the American League in innings with 85 total. He’s been a true workhorse so far, with his 2 shortest outings of the season coming in at 5.2 IP. Including his complete game shutout, he’s already gone 7 innings or more 5 different times, which he had only done once before this season.
Problem is, he’s on pace to shatter his career-high in innings at any level of his baseball career. You have to go back to High-A in 2019 to see the last time he surpassed 110 innings, when he totaled 119 in 23 starts. Last season, he finished with 106, which would’ve easily been more if he didn’t have to spend time on the IL due to a comebacker.
There’s no doubt that Houck’s 6’6”, 226 lbs frame is built to eat innings, but it’s dangerous to push him too far this season. Fortunately, his elbow has never barked since being drafted, and he’s been relatively healthy outside of a lumbar discectomy in September of 2022. Yet, for a franchise that will need Houck to lead their rotation for years to come, you need to manage him correctly down the stretch.
CLEVELAND, OH – APRIL 23: Tanner Houck #89 of the Boston Red Sox pitches against the Cleveland Guardians during the first inning at Progressive Field on April 23, 2024 in Cleveland, Ohio. (Photo by Ron Schwane/Getty Images)
Clearly, there aren’t World Series aspirations for this Red Sox team and after losing 2 in a row to the White Sox, the playoffs are feeling like a big ask with only a 12% chance of making them, per FanGraphs. So, why risk pushing Houck too hard as the season winds down? That doesn’t mean he can’t still get his work in, but that might mean shorter outings and maybe more rest between starts.
We’re seeing the Red Sox start this plan for the first time on Sunday with a bullpen game scheduled against the White Sox. This will allow for everyone on the pitching staff to basically get two extra days of rest with an off-day on Monday. Alex Cora highlighted Houck and Kutter Crawford as the biggest beneficiaries of the plan.
This isn’t meant to be a bummer, especially since it looks like the Red Sox have a top of the rotation starter locked up for the foreseeable future. It’s more of a warning to protect an important piece of your core that you finally developed correctly. Also, the handling of a situation like this can be tricky between a player and an organization, so it’s important to put the player first if you hope to pick up extension talks again in the future.
In a roller coaster of a season, Houck has been one of the few constants. It’s important that he can serve that role in the years to come, especially once Marcelo Mayer, Roman Anthony, and Kyle Teel arrive in the bigs and open this competitive window up. At that point, the expectation will be around 200 IP without a single thought and that’s before thinking about October.
BOSTON, MASSACHUSETTS – APRIL 28: Starting pitcher Tanner Houck #89 of the Boston Red Sox throws a pitch in the first inning against the Chicago Cubs at Fenway Park on April 28, 2024 in Boston, Massachusetts. (Photo by Jaiden Tripi/Getty Images)
Jun 6, 2024; Chicago, Illinois, USA; Boston Red Sox starting pitcher Tanner Houck (89) delivers a pitch against the Chicago White Sox during the first inning at Guaranteed Rate Field. Mandatory Credit: Kamil Krzaczynski-USA TODAY Sports
