Tuesday, January 22, 2008

The Truth about Slot Machines

This is a follow-up to my blog post about KENO playing. There are many misconceptions about how slot machines work, and I'd like to clear them up. Some people that play slots tend to think a slot machine is "hot", or "due to hit soon" because it hasn't hit in awhile. Hopefully I can make it clear why that isn't so.

Firstly, a slot machine works on pure probability. Every spin has the same chance to win. Let's say we have a slot machine that has a 100,000 in 1 chance to hit the jackpot. That means that every time you spin the reels, you have a 100,000 in 1 chance of hitting the jackpot. So what happens if you spin the reels exactly 100,000 times in a row? Will the jackpot hit once somewhere in those spins? The odds predict this, but it's not necessarily so. It might hit once, or it might not hit at all. Or, it might hit several times. You might hit two in a row! Or it might go a million pulls in a row without ever hitting one jackpot.

Since every pull has an equal chance to win, they are completely independent of each other. That means, if the slot hasn't hit in 90,000 consecutive spins, that does NOT mean it has 10,000 spins left before the jackpot hits. The last 90,000 spins have zero influence on what is yet to come. You can pretty much figure that any time you sit down at this slot machine, it will probably hit the jackpot sometime in the next 100,000 spins, regardless of what has happened in the past.

If you are playing on a slot machine with a progressive jackpot, you can keep a rough estimate on how long it has been since it hit. The higher the progressive, the longer it has been since the last time it hit. But, your odds of winning never change. Whether the jackpot just hit, or it has been a year since it hit, your chances of winning on each spin of the reel are exactly the same.

Some say they've never seen a jackpot hit early, but it does hit a very short time after the progressive gets very big. Why is that?

Well, if the jackpot hit very early, you probably wouldn't even notice. Say the jackpot hits and starts over at $1,000. You come back a week later at the jackpot has progressed to $1800. What you don't realize is that the jackpot may have hit again at $1200 and reset to $1000, then climbed it's way back to $1800. When the jackpot hits early, you can't really see any consequences of it.

So why does it seem to hit soon after it gets very big? It's a matter of sheer numbers: the more spins that happen, the more chances there are to hit the jackpot. Every single spin of the reels still has a 100,000 to 1 chance to hit, but if the slot gets a whopping 100,000 spins in one week, it is likely that the jackpot will hit sometime during that week. But again, it might not hit at all, or might hit several times in that week. After the jackpot is hit, the volume of spins will most certainly die down to a trickle again, at least until it builds up again.

Now you might be inclined to play the slot machine with the big progressive, and that makes sense: if you are lucky enough to hit the jackpot, it pays out better than a machine that hit recently with low progressive. But your odds of winning are no different than playing a slot machine that hit one minute ago.

This logic can be carried over to the roulette wheel. Casino's have started posting the recent numbers that have hit. But, those numbers have zero influence on future spins of the reel. You can play the same number all night, or switch numbers every spin, it really doesn't matter.

Keno is very much the same. The numbers that have hit recently have no influence on the upcoming numbers. You can play the same numbers all night, or switch numbers every ticket. It doesn't make a bit of difference in your chances to win.