Originally Posted by LeeD
On a slice, the angle of sidespin is directly related to the height of the ball at the strikezone.
As a lefty, on low balls, my slices skid severely to the right at the bounce.
On medium high balls, waist to chest, it's almost all backspin with some sidespin to the right.
On higher balls, those over my shoulders, the ball curves and bounces to my LEFT, like a rightie slice serve.
Reverse the curve directions for righties, but the medium high ball is mostly backspin with a little bit of side.
The curve of the ball in the air is related to sidespin. The direction it "kicks" after the bounce is related to spiral spin. SA calls it rotation around the "Z" axis. (I reckon the other two are "X" and "Y", but I ain't sure how to orient them to know one from the other, but I suspect that the "Y" axis is the one around which sidespin occurs.
) The height of the ball helps determine whether yer stroke causes clockwise or counterclockwise spiral spin. Just trying to help.
BTW, I've found *exactly* the same results that you've described - and utilize them regularly on droppers - especially drop *volleys*. I keep meaning to get around to doing a video for youtube. . .