question about chalk on the cue ball

poolplaya1

AzB Silver Member
Silver Member
Does anyone know what percentage of the ball is covered by an average sized chalk mark?

I am guessing it is really really small but I still want to know.

I clean the cue ball every time I break to avoid the chance of the chalk mark hitting the object ball. It really pisses me off when people hit the object balls with their stick because I never clean them at the pool hall(so I don't know how often they are cleaned) and I am just wondering if I am justified in my anger, or not.
 
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I would say you're oversensitive...... ;)

But I agree, and wipe the cue ball on all fouls if I handle the cb, and always between games.
 
If you take the surface area of the cue ball (4*pi*r^2...surface area of a sphere) and subtract the area of the cue mark, pi*r^2, you'll have your answer.
 
I would say you're oversensitive...... ;)

But I agree, and wipe the cue ball on all fouls if I handle the cb, and always between games.

I figure I make a few shots every year that I wouldn't make without cleaning the cue ball, so it is well worth it.
 
I plead guilty to sometimes hitting the object balls with my cue stick, but only if it's a bar table with a bad cue ball and no one has gotten out their good cue ball.
 
If you take the surface area of the cue ball (4*pi*r^2...surface area of a sphere) and subtract the area of the cue mark, pi*r^2, you'll have your answer.
Almost right.

Surface area of a ball (1 1/8" radius): 4 x pi x r^2 = ~16 square inches
Surface area of chalk mark (1/16" radius): pi x r^2 = ~0.012 square inch
Percentage covered by chalk mark: 0.012 / 16 = 1/1296 = ~0.08%

Of course, this doesn't account for the fact that there are probably multiple chalk marks. Let's say there are none on the OB but 10 on the CB - that raises the likelihood of a skid to about 0.8% (about 1 in every 130 shots).

pj <- for what it's worth
chgo
 
Never really think about marks on the CB. I have other things on my mind when I'm at the table.
 
Almost right.

Surface area of a ball (1 1/8" radius): 4 x pi x r^2 = ~16 square inches
Surface area of chalk mark (1/16" radius): pi x r^2 = ~0.012 square inch
Percentage covered by chalk mark: 0.012 / 16 = 1/1296 = ~0.08%

Of course, this doesn't account for the fact that there are probably multiple chalk marks. Let's say there are none on the OB but 10 on the CB - that raises the likelihood of a skid to about 0.8% (about 1 in every 130 shots).

pj <- for what it's worth
chgo

Missed that he was looking for a percentage. (More like I forgot what he wanted as I scrolled down to answer. It was pre-coffee! LOL)
 
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Thanks guys!

My guess was .02 or .03 percent, I suppose I was somewhere in the right ball park.

.8% with 10 marks? That is surprising!
 
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