Bingo (U.S.) games that award prizes to players for matching no numbers or achieving no pattern. See "Variations" for more details. The most common Bingo cards are flat pieces of cardboard or disposable paper which contain 25 squares arranged in five vertical columns and five side to side rows. Each space in the grid contains a number. A typical Bingo game utilizes the numbers 1 through 75. The five columns of the card are labeled 'B', 'I', 'N', 'G', and 'O' from left to right. The center space is usually marked "Free" or "Free Space", and is considered automatically filled. The range
Bingo card culture. Larger patterns, e.g. a diamond pattern consisting of cell positions B3, I2 and I4, N1 and N5, G2 and G4, and O3, are often used by online Bingo games to permit large number of players while ensuring only one player can win. (A unique winner is further desirable for online play where network delays and other communication interference can unfairly affect multiple winning cards. The winner would be determined by the first person to click the "Bingo!" button (emulating the shout of "Bingo!" during a live game).) In this case the number of unique winning cards is calculated as