D-backs Fall League Pitchers Statcast Takeaway
Anaylizing Statcast data on four Diamondbacks pitchers in the Arizona Fall League.
The Arizona Fall League is entering its fourth week of play. Only two of the six ballparks have Statcast data available, Salt River Fields and Camelback Ranch. Despite those limitations, there is data available on the five pitchers the Arizona Diamondbacks sent to the fall league.
Looking at the data, which encapsulates roughly two games each for Dylan Ray, Yu-Min Lin, Alfred Morillo, and Kyle Amendt. With that few of pitches, there has to be a small sample size disclaimer added, but it’s a great exercise to see pitch usage and each pitch’s effectiveness.
Here are the main takeaways for each pitcher:
Dylan Ray’s changeup is a weapon vs. lefties
Ray has developed a Devin Williams-like changeup, one that features both a high spin rate (2459 RPM) and horizontal break (18.7”). If his changeup metrics were added to the MLB leaderboard, he’d rank 4th in average spin rate and 3rd in horizontal movement.
“I looked at Devin Williams’ changeup a lot, movement-wise and the way he throws it. I just wanted a changeup that looks like a fastball out of the hand, and I would say I pronate or turn my fingers and my thumb down when I throw it. That creates the horizontal movement because the ball tilts sideways. So if I could get a straight 4-seam spin sideways, it would look more like a heater, hopefully I get more chase, swing-and-miss, and early contact [outs].”
What Ray is essentially referring to with his intent is to get as close to the 3:00 spin axis as possible. That’s a pitch with very little induced vertical break, with almost all of the movement being horizontal. Of his 28 changeups thrown in two starts at Salt River, 15 of them have an iVB of 2” or less. Overall, the pitch averages 2.6” of induced vertical break, putting it in the 2:45 axis.
The induced vertical break is a noted difference between Ray’s and Williams’ changeup. Williams has a negative iVB, which means the movement is not fighting gravity, the difference being a total of 6”. That differnce could come down to arm slot, as Ray is more overhand while Williams is three-quarters.
So far in the fall, Ray has faced 15 left-handed or switch hitters. 27 of the 76 pitches (35.5%) thrown against them have been changeups, his most utilized pitch in that split. It edges out the 4-seamer and curveball has his most effective pitch, with a whiff rate of 38.5% and a Called Strike plus whiff rate (CSW%) of 37% to lead his entire arsenal.
Lefties are 2-for-7 with a home run, hit by MLB’s No. 78 prospect Termarr Johnson back on October 8th. While there are only five batted balls, the average exit velocity is 86.5 MPH.
Yu-Min Lin lacks fastball presence, but throws a tight breaking ball
Lin fits the mold of a crafty lefty. His fastball lacks presence, with his 4-seamer averaging 91.7 MPH with 10.4” iVB and 12.4” horizontal break. The flatter shape and velocity gives him a low margin of error in terms of command to make it a playable pitch. That could mean he has to rely more on his sinker and cutter in order to change speeds on hitters.
The lack of a fastball presence is a bit disappointing since he can spin a very tight breaking ball. The slider averages 2762 RPM and the curveball over 3000. As a result, both pitches get a lot of horizontal sweep, with the slider averaging 10” and the curveball 11.4” horizontal break. The slider is his biggest swing-and-miss pitch against lefties, getting a whiff rate of 33.3% against same-handed hitters.
The lack of size and fastball presence really works against him as a starter, but he has the arsenal to be an effective reliever should that come to pass.
Alfred Morillo is blowing fastballs by hitters
Morillo is the least experienced arm in the organization, playing all of 2024 with High-A Hillsboro. But in the fall league, he has been the circuit’s most dominant reliever. In four appearances, he has allowed just one baserunner in five innings and struck out 9 of the 16 hitters faced.
Looking at the data, the pitch that has stood out the most has been his 4-seamer. It averages 95.3 MPH and has a ridiculous CSW% of 59% on 30 tracked pitches. Of his 17 4-seamers thrown, he has 4 whiffs and 6 called strikes. It’s also been a big putaway pitch, registering a strikeout on three of the four times (75%) he threw it in two-strike counts.
Another notable characteristic has been his ability to generate ground ball contact. Of the two batted balls against him in the metrics, both are ground ball outs. With the potential ability to miss bats and get hitters to beat the ball into the ground if they make contact, he should fly up the system in 2025.
One pitch that has caught my attention that hasn’t gotten a clear classification is the “sinker”. The spin rate of the pitch (1692) is 600 RPM lower than the 4-seamer (2254), which makes me suspicious of the calling. Based on the fact it’s averaging 92 MPH, it could be either a very firm changeup or a split-finger fastball. The grip would be very telling of the pitch type.
Kyle Amendt gets insane vertical break on his 4-seamer
Amendt doesn’t have exceptional velocity or spin numbers, but he gets an insane amount of induced vertical break on his 4-seamer. Even though it’s clocking in at 90.8 MPH and a spin rate of 2148 RPM, it’s averaging 19.8” iVB.
It would not be surprising if Amendt ranks amongst the leaders in active spin rate, or the percent of spin that contributes to the movement of the pitch. Add in an over-the-top arm angle, and you have one of the most efficient 4-seam fastballs in terms of movement relative to spin.
The arm angle was a result of him trying to learn a curveball. Throwing a three-quarters arm slot out of high school, the need to develop a secondary pitch (curveball) altered the arm slot to its current version. Taking inspiration from Adam Wainwright and Clayton Kershaw, he’s developed a 12-6 breaker that has only 2.4” of arm-side break.
It’s a bit unusual, but that could play into the effectiveness of the pitch due to its uniqueness. Only 4 MLB pitchers have a curveball that features arm-side break on average.