The division by two for each of the 'I', 'N', and 'G' columns is necessary to once again remove redundant number combinations, such as and in the N column.
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 (15 2*(15*14) 3/2 3) = 260,465,625 (260 million). (A unique winner is further desirable for online play where network delays and other communication interference can unfairly affect multiple winning cards. 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. The single-pattern #3 row has already been mentioned, but its limited card set causes problems for the emerging online Bingo culture. However, it is more practical and manageable to use card sets that avoid multiple-pattern games. The solution is to name the player who shouts 'Bingo!' first, is the winner. The challenge of a multiple-pattern game is selecting a winner wherein a tie is possible.
