Patrick Johnson
Verified Member
- Joined
- Jul 31, 2008
- Messages
- 1,447
[WARNING: SCIENCE AHEAD - TURN BACK NOW!]
Most of us know that hitting a cut shot with outside sidespin can eliminate ball/ball friction and the resulting contact throw, if the amount of sidespin is just right for that cut angle. But if we apply too little or too much sidespin, then throw isn't fully eliminated (and may be increased or even reversed).
Is there a simple way to know in advance how much sidespin is the right amount to just eliminate contact throw? Here's a simple method that I dreamed up, using the fractional CB/OB overlap for the cut angle you're shooting and the fraction of maximum sidespin you're applying. The general rule is:
"Gearing" (no throw) sidespin = the fraction of maximum sidespin that, when added to the CB/OB overlap fraction, totals 1.
In other words,
- 3/4 ball hit: 1/4 maximum sidespin*
- 1/2 ball hit: 1/2 maximum sidespin*
- 1/4 ball hit: 3/4 maximum sidespin*
Note 1: Of course the amount of sidespin you want usually depends on where you want the CB to go, so usually this technique can only tell you how close your desired sidespin is to the no-throw amount.
Note 2: Maximum sidespin = 1/2 distance from CB center to edge.
Hope it helps somebody (or is at least interesting),
pj
chgo
*For you geometry geeks (I know you're out there
): the precise sidespin fraction is 80% of the above amounts, but that's too much math for a rule of thumb (especially one based on imprecise estimated cut angle fractions).
Most of us know that hitting a cut shot with outside sidespin can eliminate ball/ball friction and the resulting contact throw, if the amount of sidespin is just right for that cut angle. But if we apply too little or too much sidespin, then throw isn't fully eliminated (and may be increased or even reversed).
Is there a simple way to know in advance how much sidespin is the right amount to just eliminate contact throw? Here's a simple method that I dreamed up, using the fractional CB/OB overlap for the cut angle you're shooting and the fraction of maximum sidespin you're applying. The general rule is:
"Gearing" (no throw) sidespin = the fraction of maximum sidespin that, when added to the CB/OB overlap fraction, totals 1.
In other words,
- 3/4 ball hit: 1/4 maximum sidespin*
- 1/2 ball hit: 1/2 maximum sidespin*
- 1/4 ball hit: 3/4 maximum sidespin*
Note 1: Of course the amount of sidespin you want usually depends on where you want the CB to go, so usually this technique can only tell you how close your desired sidespin is to the no-throw amount.
Note 2: Maximum sidespin = 1/2 distance from CB center to edge.
Hope it helps somebody (or is at least interesting),
pj
chgo
*For you geometry geeks (I know you're out there
): the precise sidespin fraction is 80% of the above amounts, but that's too much math for a rule of thumb (especially one based on imprecise estimated cut angle fractions).
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