The Hit Frequency Counts

There are two numbers that must be taken with the utmost seriousness by slot players—the return percentage (sometimes called payout percentage) and the hit frequency.

Every slot player knows about the first number. In fact, many casinos publicize this number and brag about it. The return percentage indicates how much of each dollar wagered the machine gives back. Thus, if a casino advertises that a certain machine is certified to give back 98 percent, it will give back 98 cents on the dollar in the long run. That means if $100 is played through that machine 98 dollars will be returned. The casino keeps two dollars. Their edge or vig is two percent, their payback 98 percent.

Naturally, the return percentage is not a smooth number. A player doesn't put $100 in and get $98 back each and every time. Sometimes he puts $100 in and gets nothing. Sometimes he puts one dollar in and gets a huge win. The return percentage is a long-term figure, operating over many millions of decisions. However, at the end of a year of play, just about any machine that has been played a reasonable amount of time will be returning at or close to its programming. Oh, yes, the return percentage is programmed into the machine. Even though the RNG selects which symbols it will pick in a random fashion, all such picks are made on the basis of how much the machine will return to the player.

Let me give an easy demonstration. Take a coin flip, which is also a strictly random event (assuming the flipper isn't fooling with the results). You have a 50-50 chance of heads or tails showing. You bet $100 on heads on each and every flip. Every time tails shows, you lose $100. But every time heads shows, you win $98. So you win one and lose one, and you're down two dollars for the $200 that you risked. The casino has a one percent edge on you (for every $100 you bet, you lose one dollar). In a somewhat more complicated way, the slot machine is doing the same thing. It is not returning the true odds of all the probabilities that you face when you play your money. It is keeping a little for the casino.

The "hit frequency" is another thing altogether. This number tells on what percentage of spins the machine will return money to you. A coin flip where you bet either heads or tails has a 50 percent hit frequency. You will win 50 percent of the decisions. In our example above, however, even though you win half the time, you actually lose two dollars because of the house edge. On a slot machine, you can "hit" something and still lose as well. If you put in three coins and get two coins returned, you "hit" but you also lost. The hit frequency is not the "win" frequency as it is with flipping a coin. Theoretically, you could have a machine that "hits" on every decision—a 100 percent hit frequency machine—and lose on each and every spin. Of course, if any casino installed such a high "hit," no-win machine, that casino would find itself without customers in short order. Imagine playing several hundred or several thousand spins and always getting a fraction of the coins back that you played on each and every spin. Boring.

In such a case, you could find a 100 percent "hit" machine that didn't shortchange you. How? By going to the change machine and playing that!

Obviously, casinos are not owned or staffed by idiots. Casino managers know that machines must be programmed in such a way as to give the player enough "hits" and also enough big hits (some of which make for winning sessions) in order to keep them playing. How is this done?

The hit frequency range for most machines hovers around the 15 percent mark. I have read about machines that go as low as an eight or nine percent hit frequency and as high as a 30-40 percent hit frequency. A 15 percent hit frequency means that one of every six spins will result in some money being returned to the player (again, not necessarily a win). Within this 15 percent of hits, one or two percent will be for interesting sums. So in 1,000 spins, 150 will return something but one, two or three of these will return something substantial enough to keep players wishing and hoping. But the truly big jackpots, those dream moments, are only a tiny fraction of a percent of that 15 percent of hits.

Like the return percentage, the hit frequency is not smooth. For every six spins you don't necessarily win one—you could go 10, 12, 30 or 40 spins without getting anything back. John Robison, managing editor of this site, once went over 70 spins without a single hit! Of course, you could win a few in a row, lose a bunch, hit some, lose some and so on. But in the long run, you will find that the machine hits once every six times on average.

Understanding return percentage and hit frequency numbers allows us to understand several important aspects about slot play, such as why winning streaks are not as long as losing streaks; why winning streaks can be explosively big, why machines seem to pay out like crazy and then "freeze up." In future RGT articles, I shall address the most frequently asked questions concerning slot machines. Frankly speaking, if you love to play, you'll love to play them even more when you know even more about them.

For more information about slots and video poker, we recommend: