Miguel Castro’s Improved Changeup is Becoming a Weapon

While building a reliable pitching staff has proven to be extremely challenging over the last few seasons, the New York Mets aren’t experiencing those same issues so far this season as their bullpen has excelled through the first three weeks of the 2021 campaign.

Even though reliever Seth Lugo hasn’t thrown a single pitch in 2021, the Mets’ bullpen hasn’t become a liability like some experts may have thought it would. With impressive contributions from pitchers like Edwin Diaz, Jeurys Familia and Miguel Castro, this club hasn’t thrown away nearly as many leads as they did last season.

Despite adding a pair of quality arms over the offseason, in Trevor May and Aaron Loup, one of the team’s most productive relievers up to this point wasn’t even acquired by this current regime.

Coming over at last season’s trade deadline, Castro was sent from the Baltimore Orioles in exchange for prospects Victor Gonzalez and Kevin Smith, and the early results from this acquisition are proving to be very rewarding for the Mets.

While the 26-year-old was shaky at times throughout the second half of the 2020 campaign, in which he posted a 4.00 ERA, 4.19 FIP and a 4.46 xFIP over 9.0 innings, the right-hander was determined to improve his performance during the following season and he’s certainly delivering on that promise early on.

Over his seven appearances, the 6′ 7″ reliever has compiled 7.0 innings, producing a 2.57 ERA, 0.52 FIP, 11 FIP-, 1.51 xFIP, 35 xFIP-, 40.0% strikeout rate (career-high), 37.5% whiff rate, 6.7% walk rate, 18.8% LD rate, 56.3% GB rate, 25.0% FB rate and a 0.4 fWAR rating, which has already matched his career-high rating from the 2019 campaign.

Comparing his stellar results to the rest of the majors, the former Oriole is currently tied for the third-highest fWAR and owns the fourth-best FIP and FIP-, the sixth-best xFIP and xFIP-, and is also tied for the 13th-highest strikeout rate among all qualified relievers, according to FanGraphs.com.

Along with Castro’s determination to evolve his craft in 2021, part of his transformation has included making a slight adjustment to his pitch selection, as he’s significantly increased the usage of his low-90s changeup. Early in his career, the hard-throwing righty utilized his off-speed weapon anywhere from 5% to 17%. This year, he’s become much more comfortable with the pitch and has started throwing it around 28% of the time.

In addition to adjusting his changeup’s usage, the Dominican native has also experimented with the speed of his third offering.

Throughout his career, average velocity for Castro’s changeup has ranged from 86 mph to 92 mph. However last year, the pitch averaged a career-high 92.3 mph.

This year, the average velocity on the change-up has dipped down to 91.0 mph this season and he’s been experiencing far more success with it.

Thanks to this minor drop in velocity, Castro’s changeup has increased both its vertical and horizontal movements, resulting in an average of 32.1 inches of drop, an increase of 3.4 inches from last season.

As for its side-to-side movements, his off-speed pitch is now averaging 19.8 inches of break, which is tied for fourth-highest in the majors, and has increased by 1.5 inches since 2020.

Combining all of these crucial factors, Castro has been able to locate his changeup more effectively during his first full season with the Mets. As a result, these adjustments have helped him primarily position one of his most-trusted offerings low-and-away to left-handers and low-and-inside to right-handers.

Here’s where Castro has located his changeup this season:

And here’s where it was thrown last season:

Though Castro’s changeup has served as a reliable third weapon throughout his career, making these pivotal adjustments during the offseason and this past spring has transformed it into an elite pitch, especially against left-handed hitters.

Utilizing it 56.0% of the time against lefties this season – the highest usage among all of his pitches – the towering righty has produced a .250 AVG (.066 decrease from 2020), .200 xAVG (.037 decrease), .250 SLG (.434 decrease), .277 xSLG (.119 decrease), .221 wOBA (.219 decrease), .204 xwOBA (.107 decrease), 45.0% whiff rate (10.0% increase), 46.2% in zone whiff rate (21.2% increase), 46.7% chase rate (7.7% increase), 80.0% GB rate (34.5% increase) and a -6 average launch angle (15-degree decrease).

In comparison to the rest of the majors, the former top prospect’s off-speed pitch has generated the ninth-highest whiff rate, the 12th-highest strikeout rate (37.5%) and the 12th-lowest xwOBA among all pitchers with at least 10 plate appearances against their changeup, according to BaseballSavant.com.

Despite allowing a 60.0% hard-hit rate against left-handed batters in 2021, Castro’s ability to prevent those hitters from putting his changeup in the air is one of the biggest reasons he’s enjoyed so much success with it up to this point. Since his primary weapon against lefties can also induce a ton of swings-and-misses, there’s a very strong chance these stellar metrics can be sustainable the rest of the way.

But considering the young right-hander’s overall hard-hit rate (56.3%) sits in the bottom three percent of the majors, he still has plenty of room to grow through the rest of this season. Especially since his high-90s sinker currently owns the highest hard-hit rate (75.0%) and LD rate (37.5%) among all three of his pitches.

If Castro can continue performing effectively with his changeup and also make some much-needed adjustments to his sinker, chances are he’ll be able to keep his high-leverage role in the seventh and eighth innings moving forward.