This pitch will help Red Sox pitcher Tanner Houck stick in the rotation

Red Sox starter Tanner Houck has a plan to stick in the rotation

The Boston Red Sox focused on stockpiling arms for their starting rotation prior to when the lockout brought the offseason to a halt. Depth will be vital to navigating the grueling schedule but the additional rotation options put the role of Tanner Houck in question entering the 2022 season.

Houck bounced between the rotation and the bullpen last season, making 13 starts along with five relief appearances. He’s capable of thriving in either role but Houck undoubtedly views himself as a starting pitcher and he’s intent on cementing his spot in the Red Sox rotation.

The primary reason why the Red Sox haven’t locked Houck into their rotation is their reluctance to leave him on the mound long enough to face the opposing lineup for a third time. Opposing hitters faced Houck for a third time in the game in only 18 plate appearances last season and they hit a blistering .467 with a 1.489 OPS in that limited sample. This explains why Houck only made it through five innings in five of his 13 starts and never made it through six last season. He will need to last at least five innings more consistently in order to stick in the rotation.

During an appearance on WEEI’s Live BP podcast, Houck explained the challenge of facing hitters who are game-planning for him with the benefit of advancements in technology and scouting. He’s learned that he needs to adapt when facing hitters the second time through the order by showing them something they might not be expecting based on their prior plate appearance. Keeping hitters guessing for a third time is more challenging with a limited arsenal, which is why developing his split-finger fastball is the key to lasting deeper into games.

"“The biggest thing before was not having a true secondary off speed pitch that could also complement the slider,” Houck explained. “I think the splitter is an incredible pitch to pair with that, especially where it was last year when I was throwing it 84-87 mph. The year prior whenever I started throwing it the pitch was like 89-91 mph, maybe 92. And my two-seam fastball is anywhere between 91-93 mph. Four-seam fastball is 93-95 mph. So in my opinion the splitter was too close of a movement profile to the two-seam and in velo. So at the end of the year I was throwing it and it was like 85, 87, good movement. I was like, ‘OK, that’s a good separation in terms of velo off the fastball.’ It’s still somewhat similar in the movement profile, but the velo was enough where they couldn’t sit on that anymore. And they also have to respect the four-seam, the two-seam and the slider.”"

Houck is primarily a fastball-slider pitcher. His four-seam fastball (38.6%) and slider (37.1%) were utilized almost equally and he mixed in a two-seam sinker (17%), per Baseball Savant.

The splitter is a pitch he experimented with more last season but he used it almost exclusively against lefties. Houck threw 85 splitters last season, only 12 of which were to a right-handed batter. The results were excellent, as Houck held hitters to a .059 batting average with his splitter. It’s a tiny sample size though. If he can expand his usage of the splitter to mix it in against hitters from both sides of the plate while maintaining similar dominance with the pitch, it will go a long way toward finding success against hitters he’s seeing for a third time through the order.

Houck also discussed how he intends to push himself by working on locating his other pitches in different spots. Throwing a backdoor slider or elevating the four-seamer up arm-side are examples of ways he can expand upon his primary pitches to keep hitters off balance.

The splitter is the key though. Houck doesn’t have a significant amount of differential in velocity between his four-seam (94.5 mph) and sinker (93.2 mph). The similarities in velocity and movement to the sinker made the right-hander hesitant to use the splitter against right-handed hitters. The adjustments he’s made to the splitter help differentiate the pitch, which should allow him to be comfortable enough to mix it in more frequently.

His velocity isn’t overwhelming but a mid-90s fastball with good movement and solid command has been very effective. Houck’s four-seamer allowed a .307 wOBA that ranked 59th out of 239 major league pitchers (minimum 100 plate appearances). His filthy slider held opposing hitters to a .159 batting average and .216 wOBA while generating a 42.4 Whiff% that easily made the pitch his best asset for missing bats. Houck has plenty of confidence in these pitches but he knows it’s not enough.

"“No matter how nasty your stuff is they will eventually get a hit if you throw the same thing over and over,” said Houck."

The 25-year-old is still learning, still developing his pitches. Many questioned if Houck’s long-term future would be in the rotation but the lack of success he found when facing hitters for a third time through the order isn’t necessarily a permanent flaw. Houck recognizes that he needs to improve by mixing up his pitches more and he’s clearly making progress in that area.