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:

When using the 30° rule, you need to shift the peace-sign down the tangent line with faster speeds, to predict the final CB direction. Speed effects on CB paths are demonstrated in these videos:

For more information, see “90° and 30° Rule Follow-up – Part V: the final chapter” (June, 2005) and “Draw Shot Primer – Part I: physics” (January, 2006). 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. 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.

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