Top 40 Pitching Prospects (Midseason Update)
Analysis of the top 40 arms in the minor leagues accompanied by Stuff+ on EVERY arm
If you’re receiving this post in your email inbox, I encourage you to go to my substack site to read. The functionality of the tables will be much friendlier.
This is an update of my top 40 pitching prospects list I initially constructed in Spring Training. Much of the writing below will reflect and expand on my prior musings on each arm. I encourage you to read that list right here.
The value-add of my list compared to the many other fantastic lists out there is that I have access to minor league pitch shape data for all levels. I focus on the shapes a pitcher creates a lot. And I’ve enlisted the help of Thomas Nestico to let me use his Stuff+ model to better understand the major league quality of these minor league pitches.
Stuff Notes…
For individual pitch types, Stuff+ shows that pitch’s value relative to other pitches of that pitch type. A 124 Stuff+ slider is 2 standard deviations (plus-plus) above the average MLB slider. This would equate to a pitch around the 98th percentile in MLB—a rare offering to find in the minors.
Total Stuff+ distills the value of an entire repertoire into one number based on the usage of that pitch and the value each specific pitch type has towards run prevention. Therefore, a 100 Stuff+ curveball has a different contribution to run prevention than a 100 Stuff+ fastball.
A pitcher with a total Stuff+ of 112 would have an arsenal 1 standard deviation above the MLB average at preventing runs or an 85th-percentile MLB mix.
This scaling is slightly different compared to Eno Sarris’s model on FanGraphs, which also has a standard deviation of 12 for total Stuff+, but on an individual pitch level, has a higher standard deviation. This Stuff+ may feel slightly deflated. That’s normal. These aren’t major league pitchers (yet).
Data notes for reference (all MLB):
Average righty 4S is 94 mph with 16” induced vertical break and 8” arm-side movement from a 5.8’ release with 6.4’ extension.
Average four-seam swing miss is 22%. Average slider swing miss is 33%
Average four-seam zone rate is 55%. Average slider zone rate is 45%
Average four-seam chase is 20%. Average slider chase is 24%
In the past, I did not rank pitchers who threw in MLB games. Given the number of promotions, I’ve decided to make an adjustment and take players off when they graduate from prospect lists. With that said, here are some recent graduates and players who have fallen off the spring list that are still prospect eligible:
Graduates: Paul Skenes (previously #2, should’ve been #1), Jared Jones (previously #10, feel good about that rank), Christian Scott (#21, could’ve been higher), Ben Brown (previously #33), Spencer Schwellenbach (recent graduate, would’ve been #14 on this list)
Fell off list (with former rank): Nick Nastrini (#36), Daniel Espino (#31), Henry Lalane (#34), Mick Abel (#23), Wilmer Flores (#37), Ty Madden (#22), Jack Leiter (#14), Jackson Baumeister (#40), Carson Whisenhunt (#33), Marco Raya (#19), Justin Wrobleski (#38), Chase Petty (#30)