Bingo cards are often used in casinos and other gaming establishments to help players determine the amount of their winnings. A Bingo card has spaces for numbers 1 through 75, which represent different numbers of Bingo points.
Some bingo cards also have spaces for bonus rounds or other bonuses.
Many players believe that the blank spaces on some bingo cards are there for a reason. Some say that the casinos use these spaces to keep track of how many bonus rounds a player has won, or how many points they have earned in a particular game.
Others believe that the casinos use the blank spaces to randomly assign Bingo points to players, which makes it more difficult for players to predict their Bingo point totals.
The reason behind this mystery is still unknown, but it is an interesting theory nonetheless.