What effect does shot speed have on the 90° and 30° rules?
Shot speed has no effect on the 90° rule. With a stun shot, the CB heads straight down the tangent line, regardless of speed.
With follow and draw shots, the CB persists along the tangent line longer before curving to the final direction, as demonstrated in this video:
Follow and draw are delayed even more if the CB hops into the OB. For more information and demonstrations, see the ball hop effects resource page.
When using the 30° rule, this diagram shows how you need to shift the peace-sign down the tangent line with faster speeds, to predict the final CB direction:
For more information, see “90° and 30° Rule Follow-up – Part V: the final chapter” (June, 2005).
With draw shots, a similar shift with speed occurs, based on this diagram:
For more information, see “Draw Shot Primer – Part I: physics” (January, 2006).
The condition of the cloth also has an effect. With a slicker cloth, the CB persists along the tangent line longer before curving to the final direction. For more info, see cloth effects.