Aidan Cooke- Miguel Castro Looks Ready to Take the Next Step in 2021

     It's still early, but Miguel Castro is having himself a spring. Through 5.1 innings pitched, Castro has kept the opposition off the scoreboard, allowing just one walk and one single while punching out seven. His one hit allowed was a single that blooped just short of Nimmo's glove in center. 

     Miguel has been a trendy pick to break out for a few seasons now, thanks to his intriguing arsenal of pitches. He mixes a sinker, slider, and changeup, all of which are thrown with well-above-average velocity and movement. However, he has never been able to put them together and have great results, with a career 4.29 ERA and 1.43 WHIP through 283.0 innings.

    Starting with his least-used pitch, Miguel's changeup has been a very solid part of his repertoire, even if it has never been thrown more than 20% of the time. Castro throws it hard, averaging 92.3 MPH last season, the fastest of any changeup thrown at least 50 times. He also gets plenty of dance on this pitch, as it moved an average of 18.2 inches horizontally, the third-highest horizontal movement of any changeup in the same sample size last year. 

    Castro introduced his sinker to his pitch mix in 2017 when it sat around 95 MPH. In 2018, it remained around the same but rose up to 97 MPH in 2019 and 98 in 2020. That number was the 6th-highest average velocity of the 370 sinkers thrown at least 100 times last season. It doesn't move much vertically, but Castro's sinker, like all of his pitches, gets good horizontal movement, averaging 17.8 inches, a number that was good for 9th among sinkers tossed at least 100 times. 

    Despite its movement and velocity, Castros' sinker has historically been his worst pitch. In 2019, opposing hitters had a .346 batting average, .583 SLG, and .424 wOBA against his sinker. Last year, batters hit .362 with a .574 SLG and .430 wOBA. Even though these surface-level stats worsened, the advanced metrics indicate that Castro's sinker actually improved. In 2019, the expected batting average against was .312, but that fell to .266 in 2020. The xSLG improved from .544 to .441 and the xWOBA also upgraded from .402 to .347. 

    Even with the expected statistics showing that Castro's sinker has been rather unlucky, his slider is still definitely the best pitch in his arsenal. From 2016-19, his slider's xWOBA improved every year, starting at a good .264 and ending with a dominant .187. It climbed to .206 in 2020, which is still an outstanding mark. Castro had gotten a healthy amount of swings and misses his slider coming into 2020 but increased that number by 10%, all the way to a 47.5 whiff%. This doesn't seem like an outlier that should be quickly dismissed either. He had had a 53.8% whiff rate in 2016 and a 41.7% rate in 2017. The uptick in swings and misses certainly helped Miguel's strikeouts, as he had a career-best 33.3% K rate in 2020.

    He had only thrown it about 30% of the time through his career, but over the spring Castro has upped the usage, now having more than half of his pitches be sliders and lessening the number of sinkers thrown. The results speak for themselves, and Castro's pitches have looked even better. In his last appearance, his slider was averaging 38 inches of vertical break, 4 more than his average last season, and his average velocity was also up by 0.7 MPH.  He threw the pitch 8 times and got 2 called strikes, 3 swings, and 3 misses. 

    What has been a recurring problem for Castro throughout his career is free passes. Since 2018, Castro has allowed 5.00 BB/9 from 101 walks in 181.2 innings. Given the hard break he gets on his pitches, it isn't hard to see why Castro allows so many walks. Miguel does seem to be improving his control, though; after having a career-worst 13.3 BB% in 2018, he shrunk it to 12.9% in 2019 and 9.9% in 2020. And as great as Castro has been in spring training, the number that sticks out to me the most is his one walk allowed in 5.1 innings. 

    There is reason to believe Castro can continue to improve his control, too. One factor that could help Castro is the addition of James McCann to the roster. Last offseason, McCann altered his setup and stance behind the plate to improve his framing, and it paid off. His strike rate on the edges of the zone jumped from 44.9% in 2019 to 51.4%, the 8th-best mark among qualified catchers. This could be especially beneficial for Castro since he primarily locates his pitches in the lower portion of the zone. Here are contour plots of Castro's sinker, slider, and changeup location (left to right) from 2019, taken from Baseball Savant.

    Evidently, Castro's pitches teeter on the lower edge of the zone, right where McCann is the strongest at getting strikes. Two of the Mets' primary catchers last season, Wilson Ramos and Robinson Chirinos, struggled to get strike calls in this area. Castro's former catchers in Baltimore, Pedro Severino and Chance Sisco, also failed to get many strike calls in that portion of the zone. With a few extra strikes here and there from McCann, Castro could improve his strikeouts and chase rate. 

    With a refined repertoire, improved control, and a new backstop behind the plate, Miguel Castro looks poised to put his shaky years behind him and play a major role in this season's bullpen.