The term slot can refer to the narrow aperture or groove on the side of a container that holds a product. It can also be used to describe the place in a game of chance where one may insert a coin or paper note. Alternatively, slot can refer to the position of a particular player on a betting line in a table game.

In the early days of slot machines, players would insert cash or, in “ticket-in, ticket-out” machine, a paper ticket with a barcode into a designated slot. The machine would then spin reels that contained symbols based on a theme, with the highest payout being awarded for three aligned liberty bells. Today, slot machines have microprocessors and assign a probability to each symbol that appears on the reels. The result is that a winning combination might appear to be “so close” but actually has a much lower probability than other combinations.

Despite Hirsch’s criticism, the innovations and changes led by William “Si” Redd turned slots from a sleepy, ignored afterthought on casino floors to the industry’s leading source of revenue. The UNLV Oral History Research Center includes an extensive interview with Redd, whose ideas and actions transformed the form and function of slot machines.

Many people believe that slot machines have a tendency to pay out after a cold streak, or that they are more likely to pay out when the jackpot is large. These beliefs are based on the idea that a machine will return more often if it is hot, which is false. Instead, a random number generator runs thousands of numbers per second to determine whether or not a particular spin will yield a win.