balls

• colors
• contact time
• effects of Slicone spray
• types for different games
• weights

colors

Is there any rationale behind the choices for pool balls?

from Patrick Johnson:

Three primary colors:
1 & 9 = Yellow (primary)
2 & 10 = Blue (primary)
3 & 11 = Red (primary)

Three secondary colors:
4 & 12 = Purple (blue+red)
5 & 13 = Orange (red+yellow)
6 & 14 = Green (yellow+blue)

One tertiary color:
7 & 15 = Maroon (purple+red)

Two all-or-nothing colors:
8 = Black
Cue = White

contact time

How long are the CB and OB in contact during a collision?

Marlow did some experiments on this, and he reported numbers between 0.0001 and 0.0006 seconds. The balls don't stay in contact for very long.

effects of Slicone spray

Does Silicone spray help you get more draw and masse action on the CB?

Yes. In fact, some trick shot artists sometimes use Silicone spray to help them create some of the magical shots they can execute.

I describe and demonstrate the effects of Silicone spray in this video (starting at the 0:40 point):

NV B.40 - Masse-draw billiard (carom) trick shot from the movie "The Hustler"

Here's another (at the 0:35 point):

NV B.41 - Coriolis masse shot aiming method with a large-curve example

It works like a charm, but it does wear off over time as it wipes off onto the cloth. It also leaves slippery residue on your hands when you handle the CB.

weight

Does the weight of the balls ever vary much, and does it have an effect?

Generally, with older balls, the cue ball (CB) will be slightly lighter than the object balls (OBs) because it takes more abuse and wears faster. However, if a new CB is used with an older set of OBs, the CB will be slightly heavier because only the OBs will have wear. On many coin-operated tables in bars (i.e., "bar boxes"), the CB is often heavier and/or larger than the other balls to help the ball-return mechanism distinguish the CB from the others.

When the CB is heavier, it is easier to follow and tougher to draw. With a cut shot, the CB will go forward of the tangent line; and with a stop shot, the CB will drift forward some.

When the CB is lighter, it is easier to draw the CB and tougher to follow. With a cut shot, the CB will pull back from the tangent line; also, with a stop shot, the CB will bounce back some.

from sfleinen:

On any non-coin-op table (or tables that do not have a dedicated cue ball return), the cue ball is the same size, weight, and density as the rest of the object balls. The descriptions mentioned thus far about the stop/stun shots hold true; a straight-in shot hit with stun results in a stop shot. That is, when hit perfectly, the cue ball stops right at the contact perimeter (one ball contact away) of where the object ball once stood. Nearly perfect transfer of energy from the moving object (the cue ball) to the stationary object (the object ball) because of equal mass.

However, on a coin-op bar table (or any size table that has a dedicated cue ball return), you are most likely dealing with either an oversize, overweight, or magnetic cue ball -- which changes the cue ball -to- object ball size/weight/density. The cue ball is heavier. Whenever a moving heavier body hits a stationary lighter object, not all the energy is transferred -- some stays with the cue ball. So you'll find that on bar / coin-op / cueball-return tables (other than Diamond's SmartTables which use an optical sensor), the cue ball slides forward into the space occupied by the object ball, before the stun/stop/draw/follow takes effect. How much of a slide occurs is determined by how hard the shot is hit -- harder = deeper cue ball slide into the area formerly occupied by the object ball, perhaps even beyond that space.

This is detailed in the [great book] 8-ball Bible and understanding this phenomenon is crucial to good bar table play.

One can actually see this phenomenon in action with a heavy cue ball. The Aramith Red Dot Dynamo is perhaps the heaviest cue ball on the market, weighing in at 6.75 ounces (approximately 192 grams). By way of comparison, most object balls weigh in at 5.75 ounces (approximately 164 grams), so there's a full ounce of cue ball that still has undissipated / non-transferred energy after a stun collision with an object ball. That energy has to go somewhere -- and that's continued forward motion. Even with heavy draw applied, one can smash an Aramith Red Dot Dynamo, and it will slide into the space where the object ball once stood (or beyond that space, depending on how hard you hit it), and you can observe the draw taking effect only after the excess "leftover energy" has been burned up as forward motion into that object ball's previous space. A hard draw shot at a slight angle to the object ball results in a peculiar (but pretty!) "J-hook" motion, that's used by some accomplished bar table players to avoid collision with other nearby object balls -- in essence, "J-hooking" around nearby object balls.

The same thing happens with magnetic cue balls, btw, but because they are usually not as heavy as the aforementioned Aramith Red Dot Dynamo, the effect is not as pronounced. (Magnetic balls, such as this one, weigh in at 6.125 ounces [approximately 172 grams], a little lighter than the heavyweight Aramith Red Dot Dynamo.)