One of the small but irritating disappointments of life is when a show that’s had a solid run fails to stick the landing of a finale. The ur-example of this is the universally detested Game of Thrones finale, which owes at least as much to George R.R. Martin’s legendary procrastination as it does the choices made by the showrunners, but other examples abound: Seinfeld, The Sopranos, Lost, Gilmore Girls, How I Met Your Mother, The X-Files, Gossip Girl, and scores of other long-running, once-beloved shows ended in a fashion that struck many as off-key, untrue to the heart of the show, or just plain unsatisfying, and the proportion of dissatisfaction with the ending seems directly related to how popular the show was at its peak. Nothing gold can stay, but it shouldn’t tarnish quite so quickly.
This was the case with Luis Castillo’s final two starts of the 2023 season, a pair of duds spoiling an otherwise critically acclaimed year. With the Mariners clinging to the slimmest playoff hopes, Castillo turned in two stinkers against the two teams the Mariners most needed to defeat in the Astros and Rangers. The low point was also, unfortunately, his season finale, where he lasted just 2.2 innings against a Rangers team that looked primed to attack everything in the zone and spit on anything even resembling a ball, with the normally zone-controlling Castillo giving up five walks against just four strikeouts. It was a shocking disappointment from the rock of Seattle’s rotation and, like most bad finales, wasn’t a true reflection of the heart of his season.
Pitcher wins are a deeply flawed stat, but Castillo’s 14 wins led the team, as did his 219 strikeouts—easily outpacing the next-closest Mariner in Logan Gilbert, at 189. Time after time, La Piedra took the mound and defended the Mariners against an invading army of would-be run-scorers, buying precious time for the often-sluggish offense to get started. What’s interesting is the way Castillo was able to hold off the hordes despite giving up an alarming number of hard-hit balls: a career-high 49 barrels, more than double what he gave up in 2021, with an above-MLB-average average exit velocity of 90 mph. In 2023, batters put the ball in the air against Castillo more than ever before, sending it skyward almost 28% of the time: surprising, considering Castillo now calls the more spacious T-Mobile Park home rather than Great American “Small”park.
Rather than being a sign of declining stuff, however, these changes speak more to a shift in approach for Castillo. As a Mariner, Castillo has moved away from his signature pitch as a Red, the changeup that was so effective at getting whiffs and weak contact, a necessity in the petite confines of the NL Central. In 2023, the changeup was actually Castillo’s worst pitch by a significant margin, the only one of his pitches with a negative run value. Castillo was already in the process of fading his once-signature pitch some when he was traded to Seattle, suggesting a decline in the pitch quality overall, but since he’s come to Seattle he’s revamped and reshuffled his arsenal to fit better in T-Mobile Park.
One of the key differences for Castillo is his four-seamer, a formerly unremarkable pitch that served only to set up his devastating cambio that’s now transformed into his primary weapon. In 2023, Castillo threw the heater more than he had since his debut season, but with some key differences in the pitch.
Here’s Castillo’s release point on the fastball in 2019:
And here it is in 2023:
Castillo’s arm slot is just a tad lower, as he’s coming down the mound with more forward momentum. You can see Adolis García is loaded up and in swing mode here, but he can’t catch up with this fastball that runs up and away from him at a cool 99 mph.
To make things even tougher on hitters, Castillo pairs the fastball with a sinker he can run in on righties at an almost identical velocity, maybe most famously seen in this handcuffing of Vladimir Guerrero Jr. in the 2022 playoffs:
But baiting batters with hard stuff in the zone means more swings and for Castillo, more hard contact. However, this seems to be a tradeoff Castillo and the Mariners are willing to make. After never being better than average at limiting free passes, this year Castillo ranked in the 72nd percentile in walks. Keeping free runners off the bases allowed Castillo to attack hitters in the zone more aggressively, and while he did tie his career high in home runs—the most since his first full season in the bigs, with 28—19 of those dingers came with the bases empty, suggesting Castillo is being selectively aggressive with when he’s challenging hitters on the plate.
“Contact manager” isn’t maybe the first thing you think of with a frontline starter who struck out the fourth-most batters in the AL, but between the hard stuff and a new look to his slider that’s replaced the changeup as his primary whiff-getter, Castillo is showing his ability to adapt to his new environment and continue to anchor Seattle’s defense against the endless attacking armies of the AL West offenses. It’s a skillset that looks even more valuable when considering the relatively team-friendly deal he’s signed to versus the current market for starting pitching: to echo fans of Community, here’s to six season and a (World Series) movie.