Scrabble have been sold worldwide and roughly one-third of American and half of British homes have a Scrabble set. There are around 4,000 Scrabble clubs around the world. The game is played by two to four players on a square board with a 15×15 grid of cells (individually known as "squares"), each of which accommodates a single letter tile. In official club and tournament games, play is between two players or, occasionally, between two teams each of which collaborates on a single rack. The board is marked with "premium" squares, which multiply the number of points awarded: eight dark red "triple-word"
Tile tracking the tiles are played is a standard feature of tournament play. Tracking sheets come in many varieties, and are often customized by players in an attempt to make the manual process of recording, tracking and counting tiles easier, more intuitive, and less prone to error. Accurate tile-tracking depends upon knowing the total letter distribution and letter frequency of the game and then reproducing each tile in its correct frequency to facilitate the "accounting" of each letter as tiles are played. Pre-printed forms are popular for Scrabble games because they eliminate the need to continuously create such a list for each