Starter with strong spin rate fastball is set to debut a new “spike-curve”. He may have more velocity in the tank and looks the part of a starter with “Vulcan changeup”.

A special thanks to Riley Thompson for providing some insight into his development
How acquired: MLB Draft, 11th Round, 2018
Riley Thompson was an above slot signing ($200k) by the Cubs in their impactful 2018 draft. His time at the University of Louisville wasn’t marked by success on the statline (6.82 ERA in 33 innings during his draft year), but the Cubs saw the foundation for a pitcher with strong pitching metrics coming from a college team known for developing successful pitchers.
Though he boasted excellent spin rates, a riding fastball, new changeup, and an excellent curveball, development never ends for a player who dreams of impacting a major league ballclub. According to Thompson, he’s working on his fastball development and incorporation of a new curveball leading into 2021.
Mechanics and Control
Thompson is an athletic pitcher who works with a quick tempo. He uses an over-the-top delivery, which at times could be described as “aggressive”. It has some effort to it including a pronounced headwhack, but it seems fairly repeatable. He comes with a prior injury history (Tommy John surgery 2015), but a solid durable frame. He has a pretty decent chance to start.
For as “aggressive” as I described Riley’s mechanics, he has average control. He’ll usually be around the strikezone, which allows his stuff to play up. Thompson’s command of his pitches lags a bit behind, but it’s more fringe-average than below average. A player with his profile could still succeed even with the command as it is, but he has a good chance to improve. When Thompson is on (like in his 9/14/19 5 inning, 10 K, no hit masterpiece in the MWL playoffs), you can see what he can do when he’s clicking with three pitches and average or above-average command
Pitching Arsenal
Fastball: Thompson will throw low-to-mid 90s with impressive raw spin numbers. The fastball generally sets up his offspeed pitches, but it can sit on it’s own when he’s commanding it well. He struggles a bit to get it on the inside corner to righthanders (where it really plays off his changeup). It’s a successful offering when he goes up in the zone. In isolation, the fastball is an average pitch with average command, but it really truly can’t be viewed in that way. I’d say it’s an above-average offering when played off his secondaries.
Riley described his improving fastball traits during shutdown. Considering he already boasted excellent raw spin, this pitch will be one to watch in 2021.
2019 Curveball: Thompson’s traditional grip curveball is still a dynamic pitch (especially when locating the fastball). It’s a true power curve with high spin, however the shape of the pitch has more horizontal movement than a 12-6 direction (mirroring the directions on a clock; pure vertical drop). A modification in shape could allow it to tunnel with a riding fastball up in the zone.
2021 Curveball: According to Riley, he’s worked hard to develop a new “spike-curve”. Spike-curves or knuckle-curves are immensely popular pitches recommended often by the Chicago Cubs Research & Development (R&D) gurus. Thompson says it has a true 12-6 shape now and plays off his new fastball traits. It takes a lot of trust in R&D and the player to move on from a plus pitch, but if the pitch is as promising as advertised then this curveball will be an electric offering.
Changeup: Riley adopted a different grip for his changeup nicknamed a “Vulcan-change”, resembling the Vulcan greeting from Star Trek. This new grip has shone to be a successful adoption with a penchant for fading into righthanders. Batters won’t live long and prosper when this pitch is clicking (I will not apologize). There’s a significant velocity deviation from the fastball. I don’t have the numbers on it, but it appears to “kill spin”. A changeup with low spin is a challenge for hitters facing high-spin pitchers like Thompson. I find it’s an above-average pitch.
Future Projection
Scouts even outside the organization believe that Riley Thompson has a chance to be a long-term starter. According to Matt Dorey, Thompson has made strong progress during the shutdown (likely related to his fastball and curveball development) and should get a chance to start at AA in 2021. If he succeeds, Riley may see innings in Iowa or even Chicago later in the season. It’s not impossible to see him moved to the pen later in the year to manage innings. Thompson represented a high-ceiling selection out of the 2018 draft. Thus far, Riley Thompson is making good on that decision.
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