What changed in curve ball mechanics?

I don't have a recording, but what used to work is that I spin the ball, then throw it in an arc to hit the upper right corner of the mon's circle. I throw from roughly mid screen on the left side.

I've seen others throw curves by spinning the ball, throwing to the upper right corner of the screen and having it ricochet back to the mon from there. This still seems to work, but it is not the technique that I am practiced at.