Based on how it works in the game, isn't that a better description?
if i'm not mistaken, the 'raw' movement rate i see in the editor is different from the profile, and like stuff, has other things adding into how it's used. each pitch is affected differently by movement, right? (like stuff between editor and profile(= how it's used in game) )
the arc in the air of a pitch thrown is more about what type of pitch it is, then different spin rates would create a spectrum of depth of movement for each pitch type (angular momentum and such). i think that's what "movement" is in ootp based on my perception of how it's used in above paragraph, if i am wrong, nevermind. even if right, the effort for such a minimal return wouldn't be worth it under most circumstances.
however, an idea for the next future ui overhaul that involves completely new graphics, maybe