This fastball shape stuff ties into my Hodge comment in the last post. Separating those fastballs and breaking balls is a must! This point isn't universally agreed upon by teams. Right now there's a common sentiment that vertical movement is second only to velocity, but it's definitely more nuanced about it. The Cubs, in particular, are a team that believes in incorporating fastballs with relative (or actual) cut to them for certain pitchers. Part of that is that when used well in pitch design, these pitches produce softer contact on balls in play. The relative cut added to a four-seam tends to keep it out of the true dead zone, which is where fastballs have equal horizontal and vertical movement numbers (like if a pitch had 10 inches of horizontal and 10-12 inches of vertical movement). Also we need to consider that a lot of Stuff+ calculations tend to be based on whiff% (or heavily based on that). But there's some good research and commentary- that I personally agree on - that we should be looking at run value (RV/100) since what pitchers are ultimately trying to do is prevent runs, not only generate whiffs. It's why sinkers look terrible in most Stuff+ calculations, but they aren't all bad pitches. I haven't gotten an update on Hodge's data for a few weeks, but his horizontal movement cuts the ball in a similar way to Justin Steele's. If you compare his fastball to Driveline's "Blob", Hodge's fastball is outside the dead zone here due largely to the cutting action (approx -1 inch horizontal movement and an average of 92.5 mph which was from earlier this year). And he throws this fastball from a low release height. Obviously the velocity is different, but Hodge's release height is low like Edwin Díaz. If I had to guess, I'd say the Cubs try to still get Hodge's fastball to generate more ride so it's a cut-ride fastball similar to Leeper's. Additional ride on the ball along with his release height and a mph bump or two would be pretty deadly. This is great. The bold kind of fascinates me, because incorporating whiff rate into a stuff metric seems really dumb? It feels like "Stuff" should purely be about inputs. Velocity, spin, movement, approach angle, any sort of metric you can put around deception, etc. And then concurrently, we need to improve pitcher run values. Strike %, whiff rate, exit velocity and launch angle allowed, etc. Including whiff rate in stuff+ makes it a weird in-between for a process metric vs. a results metric. It'd be like including batting average in FIP. You learn more from FIP and ERA being separate than you do by trying to take the best parts of both.