In sports betting, the term "hold" refers to the percentage of money that a sportsbook or bookmaker retains after all bets have been settled on a particular market. It's also known as the "juice," "vig," or "vigorish." The hold in sports betting represents the bookmaker's margin of profit on a given market.
Therefore, there is no way to predict when a slot machine is going to hit, and any strategy or system claiming to do so is likely to be based on superstition rather than fact.