The Chances of Hitting a Bonus on Bonus Slot Machines

Question: While I love playing penny bonus slot machines, I'm starting to wonder if they are actually worth it. For example, the other day I sat down at a machine with $40 in credit and played 30 cents a spin. I didn't hit a single bonus with that money, and lost my $40 before I could even order a drink. How common is that, and how much of a bonus slot machine's payout comes from the bonuses?

Casino developers have to walk a fine line when designing games; they need the game to be profitable for the casino while still having high enough returns and enough of an element of fun to keep players happy and playing longer. With bonus slot machines, the bonuses are the main thing that keeps players coming back, so it makes sense to have them triggered relatively often.

Playing 30 cents a spin, you would get 133 spins before your $40 runs out, and that's if you managed to never win a single credit the whole time, which is nearly impossible. Each machine is different, but it's safe to say that about a third of the payout for bonus slot machines comes from bonuses, while the rest comes from the normal game. So if the machine you were playing has a payout rate of 90%, 60% of the winnings would come from the game itself and not free spins or pick 'em bonuses.

So, if you still managed to get returns of 60% on the normal game, you would have spun the reels approximately 333 times before your $40 ran out. That's a lot of spins without a bonus. Even if we assume that the machine you were playing has a very lucrative bonus, and is therefore harder to hit, 333 games without a bonus is still far too many to keep players interested. You were most likely the victim of horrendous luck, and nothing more.

Question: I know that roulette wheels are pretty standardized and that it doesn't matter what you bet, the casino edge on roulette is always 5.26%. Why is this, though? The casino's advantage lies in the zero and double-zero, with payouts of 35-1 instead of the real odds, 37-1. But why don't some casinos pay out 36-1, for example, as a way to lure more players. How much does that affect the house edge roulette has?

Before getting to the meat and potatoes of the question, it's important to note that we are talking about the American roulette wheels found at nearly every casino in North America. American roulette wheels have both the zero and double-zero pockets, while European wheels only have the single zero. European wheels are far better for the player, as they still pay out 35-1, but the odds of actually hitting a number are 36-1, not 37-1, leaving the casino edge a much more reasonable 2.7%

It's also important to note that there is actually one bet on an American wheel which has an even bigger casino advantage than 5.26%. It's the infamous 'basket bet', which is a 5-way bet on both of the zeros, along with 1,2, and 3. It's house edge is an atrocious 7.89%

The reason casino pay out 35-1 instead of 36-1 on American roulette wheels, besides greed of course, is that it makes all the other payouts on the layout even. For example, a corner bet on 4 numbers pays out 8-1, if the house edge roulette was dropped to 36-1 though, corner bets would have to pay out 8.25-1, which would make payouts and change incredible complicated.

A casino doesn't want to go through that kind of hassle to keep the table stocked with quarters and half-dollars and figure out how to pay off a $27 corner bet. After all, the house edge if the casino paid 36-1 would be 2.63%, so if that kind of edge is what the casino wanted, it would be a lot easier for it to just use a European wheel, with the house edge of 2

About The Author

Journalist and author John Grochowski is one of the foremost experts on casinos in America. He writes a syndicated weekly gambling newspaper column and he is a frequent contributor to gambling magazines, websites, and radio programs. His books include the best-sellers The Slot Machine Answer Book and The Casino Answer Book.

  • "Turing a card over 10 times will statistically result in 5 reds and 5 blacks. If you bet $1 each time with this house edge, you would win $4.50 but lose $5. In the long run, you expect to lose $0.50, or 5% of your money."

  • "Short term results can fluctuate. Sometimes you win more than expected, sometimes you lose. This is called the standard deviation and this is what most people commonly see as 'luck'."

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