A narrow notch or opening, as in a keyway in machinery or a slit for a coin in a vending machine. Also used as a term for an allocated time and place for an aircraft to take off or land, as authorized by an airport or air-traffic control authority: 40 more slots for the new airline at U.S. airports. Also: (informal) an appointment, berth, billet, position, or slot on a team, especially in ice hockey: The captain’s spot at center is his to lose.

When slot machines were first invented, they were relatively simple with just a few paylines and a handful of symbols. But with the advent of electronic technology, these machines have become far more complex.

Today, a random-number generator inside each machine chooses a sequence of stops on the reels each time it receives a signal from the handle or button being pushed. These computer chips retain no memory, so each spin is an independent event that doesn’t take into account the results of any previous ones.

Despite this, many people believe that there is some sort of pattern to slot machines. They may notice that one type of machine seems to pay out more frequently than another, or they may see that a specific player has won the jackpot two out of every ten times they play. But these theories are based on flawed logic and don’t hold up to any actual scientific scrutiny.