Championship pool table cloth is made from a special blend of wool and nylon. The reason wool is used is to provide friction between the ball and the felt, which helps players use English on the ball for table positioning. Wool by itself will stretch which make for a shorter life expectancy. Nylon is added by interweaving the nylon into the wool for strength and longer play life.
For ball speed it is important during installation it stretch your replacement pool table cloth as tight as possible so the ball rolls with less drag from the wool thus rolling faster.