Payout percentages are the percentage amount that a slot game will pay out compared to the amount that is invested into it. If a game is set at 97% then it will only keep 3% of the money that goes into the game, and random players will walk away with the remaining 97%. But this number is never completely accurate because the payout percentage is only a theoretical number, and will only become more accurate the bigger the sample of spins gets.
There is another theoretical number that can better explain the payout percentage that a particular game is supposed to deliver. The “expected deviation” is the number that one can expect the payout percentage to be off from the percentage number, one way or another. If a player spins 1000 spins they can expect the payout percentage to be within 30-45% of the expected percentage. If there’s more spins taken in the sample, like 10,000, the deviation will be less, between 10-15% depending on the slot game you’re playing. A sample of 10,000,000 will have a deviation of only 0.3 to 0.5% from the expected payout of the game.
That shows you that any one session has no accuracy at all. Any one session could go any way and one could win or lose, it all depends on luck. So trying to find games that are due to pay out or that are running hot is a waste of your time. Having a favorite machine that you play often doesn’t increase your chances of winning unless that machine has the highest payout percentage around you at the time.
The only thing one can do is to trust that the casino is posting the truth about the long-term payout percentages and that you choose games with the biggest ones you can find. Over the long term playing games with higher payout percentages will make you a winner more often than just playing any old slot game. Find the best odds and play those games - your bankroll will thank you in the long run.