Odds of Slot Machines
First of all you should know that slot machines, as with many casino games, are a type of game for which there is no “winning strategy” - technically speaking they are a negative equity game, or –EV game for short. Unlike a game such as poker (against real opponents, not vs. the house) where proper application of skill can make a game profitable in the long-term, most casino games are designed to make this impossible.
Why Can’t I make a Consistent Return at Slots?
Let’s look at why, in the case of slots, there’s no way to make money long-term. For simplicity let’s imagine a game where there is only one pay-out, the “jackpot”, paid out for matching five symbols, of course the same logic will apply to complex modern machines as well. In this hypothetical machine there are five symbols available on each line and you need to match five of the same to win the jackpot on a $1 machine.
The lines are controlled by random number generators, and over time the five different symbols will come up equally often on each line. So the chance of hitting, say a cherry on one line is 1/5. The chance of hitting a cherry on the second line is also 1/5. Therefore the chance of hitting five cherries in a row is 1/5 x 1/5 x 1/5 x 1/5 x 1/5, or 1/3125, or 0.032%. Your odds of winning are better than this, as you can hit five bells, five whistles or five of any other set of symbols, so on this machine your odds of any set of five are actually 5 x 0.032%, or 0.16%. So once in every 625 spins of this hypothetical machine, you’ll hit your set of five identical symbols for the jackpot.
Now if the jackpot payout was $625, the machine would be a break-even proposition, as on average you’d pay $1 624 times without winning anything, and then you’d hit once in every 625 spins for the $625 prize, breaking even overall. Of course pay-outs are set by the casinos at a slightly lower figure, usually between 90% and 98% of this frequency, so for example if this imaginary machine was set for 95% pay-outs, the jackpot would actually be $594.
Of course you can get lucky and hit jackpot on your second spin, walk away and keep the money, technically making a profit. But long-term there’s no way to beat the law of averages, and the house edge will be sustained over any short-term variance in results. Rarely, certain machines are reported as paying out just above 100% over a given month, but this is again just the variance inherent in randomness, and will not be sustained over larger samples.
There’s a very nice little piece of software providing virtual testing of this principle, to be found here at Vegas Click. It simulates the return over one wager, over ten, a hundred, a thousand, ten thousand and a hundred thousand wagers, of a bet subject to a house edge, and shows the returns expected in each simulation. Try it out for yourself - it’s cheaper than going to Vegas!
A slot machine house edge is known by casino managers as the “hold”, and hold percentages vary a great deal, and do tend to be smaller at more expensive slots, frequently found to be around 1- 3% at the five dollar slots. Of course, percentage of investment lost is not a real money figure, and you’ll still tend to lose more money in real terms at the more expensive machines, since you’re putting far more money through the machine each hour.
Why Play if There’s a House Edge?
Certainly you shouldn’t be playing in order to try to make sustainable returns. Of course many people enjoy the thrill of a gamble, even if they know or merely suspect that it’s a negative equity investment of their money. Of course, there’s always the chance you may get lucky, even astoundingly so, as some winners of multi-million dollar slots jackpots can certainly attest to. There’s also the enjoyment factor, and playing slots can be a cheap form of entertainment if you stick to a budget and if you actually do genuinely enjoy it!
What is the Exact Edge on a Particular Machine?
There’s an easy answer to this one – you frequently can’t find out. Certainly it’s against a casino’s interests to publish this information on the front of a machine, and I’m sure many gambling-happy players don’t even realise there is a real house edge, nor know the difference between a game of skill and one of pure luck. Monthly and annual reports are regularly published of the actual pay-outs for given machines, so do your research and you could get a good idea.
Certain states in the US require the pay-outs to be in a certain range (typically above 80%), and this can be discovered with a bit of trawling through your state’s gambling laws. For example in Nevada, the gaming board states that the machines must have a RTP of 73% while in Mississippi, it is 80%.
A good rule of thumb is that higher cost games tend to have a smaller house hold percentage, but it’s likely to always be at least 1-3 %.