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"
Scrabble made in 1989 did not affect game play. The major changes in 1999 were as follows: In the notation system common in tournament play, columns are labeled with the letters "A-O" and rows with the numbers "1-15". (On "Scrabble" boards manufactured by Mattel as well as on the Internet Scrabble Club, rows are lettered while columns are numbered instead.) A play is usually identified in the format "xy WORD score" or "WORD xy score", where "x" denotes the column or row on which the play's main word extends, "y" denotes the second coordinate of the main word's first letter, and