In the game of bingo, it is possible to get a vertical line called a “double”. Doublebingo is a variation of the game in which players attempt to get two consecutive numbers, either both numbers of the same suit (two reds in a row, for example), or both numbers of different suits (two blacks in a row, for example).
A player can win doublebingo by getting two numbers in a row from any column.
According to some players, it is possible to get a double by playing the number seven. The number seven appears twice in a row in the first column and the second column of the bingo card.
If you want to try this at home, put seven balls into a row on the ground and draw one ball at random from each ball. If that ball is among the seven already on the ground, you have achieved your goal!.