Meet the Newest Mariners reliever, Cody Bolton

Cody Bolton is an intriguing pitcher but has much to prove. He arrived from the Pittsburgh Pirates in exchange for cash considerations and pitched to an unremarkable 6.33 ERA and 2.11 WHIP over 21 ⅓ innings in 2023. So why was Seattle interested?

Bolton spent all of 2023 bouncing between the majors and the minors and performed considerably better in AAA with the Indianapolis Indians. He had a 3.86 ERA and 1.22 WHIP over 46 ⅔ innings and even made two starts. It seemed like the plan was for Pittsburgh to develop him into a rotation piece since he made 14 minor league starts in 2022 and had a 3.09 ERA, but all of the back-and-forth likely affected his performance cycle.

Where the compelling storyline lies is in his sweeper. Despite using it just 28.8% of the time, the whiff and strikeout rates were 31.4% and 30.0%, respectively. It was a relatively small sample size of just 131 pitches, but it's still worth noting, especially given how well Seattle has been able to develop reliever talent recently (e.g., Justin Topa, Matt Brash).

His main area of improvement will be on his four-seam fastball, a pitch he used as his primary weapon this past year. Despite throwing the pitch 54.7% time, he struggled immensely to use it effectively, cobbling together whiff and strikeout rates of just 18.1% and 13.8%, far worse than his sweeper. He also had a particularly high walk rate (14.0%), a big reason for his inflated WHIP. It averaged 95.2 mph so there's potential that it becomes as lethal as his breaking pitches but it will have to be refined.

It'll be interesting to see how the Mariners decide to utilize Bolton in 2024 and whether they'll try to find a way to make him a starter or keep him in the bullpen. Either way, since he was traded for mere cash considerations, it could just be another famous experience for the PNW pitching lab we've come to know and love.