My head spins :) thinking about it, and I'm not sure what's right -- but I think what you're describing might be opposite of what is claimed in the YouTube video? I just watched it again, and I think it claims that the ball will move toward the rough side. But who knows...
Hmm, I hadn't noticed that before, but I think you may right. The slow spin must result in a lesser Magnus effect, which would allow the smooth/rough effect to dominate. That might explain the splitter movement, and perhaps knuckleball movement as well?
I guess there's a fastpitch...
OK, this thread finally got me to de-lurk, as it touches on something that I've been curious about for a while.
Are there any fastpitch movement pitches that are not based on the Magnus Force?
I'm curious because everything I've read so far on this forum has been about the Magnus Force, but...