Standard deviation is probably the most advanced slot machine strategy, yet it is quite simple to learn and implement.

All you need to do is record how many spins are needed to make before yielding a win at a slot game.

Although using paper, a pen and the precise mathematical equation to determine the number of necessary spins gives you better results, it is not needed and with a little practice you can do it using only your head.

First, you need to find a slot game, which pays out at an equal rate on every level of play since the standard deviation strategy only works with games with that payout structure.

For instance betting $10, the jackpot would be exactly 10 times bigger than playing with $1 bets.

The idea is to calculate the standard deviation of the spins between each win meaning you have to find out how many spins you have to make after a win on average before yielding another win.

In order to do that, you must play with the minimum bet for a while and record a number of spins before winning. For example if you spin 5 times and you win, you write down 5, if you win after 6 spins, you write 6. You have to repeat the cycle for at least 10 times before the standard deviation can be calculated. You also have to keep in mind that if you win back the same amount, your bet is not counted as a win.

So now when we have at least 10 numbers, say 5 5 6 6 7 7 7 8 8 9 9, we can easily calculate that the win yields at the 7th spin on average.

Now you know that in order to get the edge needed for maximizing your winnings, you can cut your losses by betting the minimum amount for 5 or 6 spins and then bet the maximum amount until you hit your win and then repeat the cycle by playing with minimum bets for 5 or 6 spins again.

Online Slot Simulator - Press the button and see how it works.
(As you can see, first the game result is defined and only afterwards the reels stop and show it)

Tip: Many Online Casinos allow pressing the button of the slot while the reels are spinning and they'll stop at the time when the button is pressed, but most people don't know that pressing the button in the middle of the game will not affect the results of the game.

The result is defined by a component called R.N.G (Random Number Generator) and this component is not affected by pressing the button in the middle of the game, the slot will show the same result weather or not you'd press the button in the middle of the game.