Question: What are the red balls known as?
About the article "Racquetball", section "Ball Colors".

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The beta-binomial distribution can also be motivated via an urn model for positive integer values of α and β, known as the Polya urn model.
Specifically, imagine an urn containing α red balls and β black balls, where random draws are made.
If a red ball is observed, then two red balls are returned to the urn.
Likewise, if a black ball is drawn, it is replaced and another black ball is added to the urn.
If this is repeated n times, then the probability of observing k red balls follows a beta-binomial distribution with parameters n,α and β.
Note that if the random draws are with simple replacement (no balls over and above the observed ball are added to the urn), then the distribution follows a binomial distribution and if the random draws are made without replacement, the distribution follows a hypergeometric distribution. 
In probability theory and statistics, Fisher's noncentral hypergeometric distribution is a generalization of the hypergeometric distribution where sampling probabilities are modified by weight factors.
Fisher's noncentral hypergeometric distribution can also be defined as the conditional distribution of two or more binomially distributed variables dependent upon their fixed sum.
The distribution may be illustrated by the following urn model.
Assume, for example, that an urn contains "m"1 red balls and "m"2 white balls, totalling "N" = "m"1 + "m"2 balls.
Each red ball has the weight ω1 and each white ball has the weight ω2.
We will say that the odds ratio is ω = ω1 / ω2.
Now we are taking balls randomly in such a way that the probability of taking a particular ball is proportional to its weight, but independent of what happens to the other balls.
The number of balls taken of a particular color follows the binomial distribution.
If the total number "n" of balls taken is known then the conditional distribution of the number of taken red balls for given "n" is Fisher's noncentral hypergeometric distribution.
To generate this distribution experimentally, we have to repeat the experiment until it happens to give "n" balls.
If we want to fix the value of "n" prior to the experiment then we have to take the balls one by one until we have "n" balls.
The balls are therefore no longer independent.
This gives a slightly different distribution known as Wallenius' noncentral hypergeometric distribution.
It is far from obvious why these two distributions are different.
See the entry for noncentral hypergeometric distributions for an explanation of the difference between these two distributions and a discussion of which distribution to use in various situations.
The two distributions are both equal to the (central) hypergeometric distribution when the odds ratio is 1.
Unfortunately, both distributions are known in the literature as "the" noncentral hypergeometric distribution.
It is important to be specific about which distribution is meant when using this name.
Fisher's noncentral hypergeometric distribution was first given the name extended hypergeometric distribution (Harkness, 1965), and some authors still use this name today. 
Four-ball is a carom billiards game.
The game is played on a pocketless table with four balls, usually one light red, one dark red, and two whites (or just two reds and two whites).
Each player is assigned one of the white balls as his own cue ball.
A point is scored when a shooter caroms on any two other balls.
Two points are scored when the player caroms on each of the three other balls.  
Traditional pressureless balls usually have a stiffer, woodier feel than pressurized balls and do not bounce as high as brand new pressurized balls.
Unlike pressurized balls, though, they do not lose bounce over time.
In fact, they get bouncier as they get lighter, due to fuzz loss.
The balder they get, the more their flight, bounce, and spin responses change from what you would expect of tennis balls.
More advanced pressureless balls, such as the TreTorn MicroX, are more similar to the feel and play of pressurized balls, and last many times longer than traditional tennis balls. 
  Dinosaur Rolling Egg Balls - It is not known what color or colors the balls where before they were re-painted as dinosaur eggs.
They are a white-yellow color as Dinosaur egg-like.
They are shaped like ovals and Kai-Lan and her friends use them in the final game of the "Dinosaur Games" olympics.
Panda Slippers - Always worn by Tolee, soft slippers that are shaped like Pandas.