When Should You Bet Big on Slot Machines?

Man in Suit Thinking With a Slot Machine Background

I always thought it would be interesting to look at when to bet big on a game that’s as close to the opposite of blackjack as I could think of. When should you bet big on slot machines?

Quite frankly, I have several opinions and lines of thinking related to how much you should risk when playing slot machines. And the conclusions I’ve come to are about as different as the conclusions I came to when discussing blackjack as you could ever imagine.

You Should NEVER Bet Big on Slot Machines

Compared to other casino games, real money slots have the ability drain your bankroll fast. Not only do slot machine games have the highest house edge in the casino, but they also practically force you to put more money into action per hour than any other game.

Betting big on slot machines basically guarantees that you’ll lose a lot of money.

The average slot machine in a competitive casino destination probably has a house edge of around 7%. It could be higher than that depending on the machine. You’re not able to determine how big the house edge, is though.

Pillar of Slot Machines

That’s because the payback percentage is based on the probability of winning multiplied by the amount you stand to win. You do this for all the possible combinations, and you have the payback percentage for the game. Subtract that from 100%, and you have the house edge for the game.

How the Payback Percentage for Slot Machines Works

Let’s look at a simplified slot machine game, slots probabilities, and how the payback percentage for the game is calculated. Let’s suppose the pay table looks like this:

  • Three fruit symbols result in a 200 for 1 payout.
  • Any two fruit symbols plus any other one symbol results in a 25 for 1 payout.
  • Any one fruit symbol plus any other two symbols results in a 5 for 1 payout.
  • Any combination without a fruit symbol but with a bar symbol results in a 1 for 1 payout.

Now, let’s say that there are 2,500 possible combinations, and you can achieve the following combinations in the following number of ways:

  • You have eight ways to get three fruit symbols.
  • You have 16 ways to get two fruit symbols plus any other symbol.
  • You have 32 ways to get any one fruit symbol plus any other two symbols.
  • You have 128 ways to get a bar without any fruit symbols.
  • Every other possible combination results in no payout.

What are the probabilities of achieving each result?

You determine that by dividing the number of ways of getting that result by the total number of possible results:

  • Getting three fruit symbols is a probability of 8/2500, or 0.0032.
  • Getting two fruit symbols plus any other symbol is a probability of 16/2500, or 0.0064.
  • Getting one fruit symbol plus any other two symbols is a probability of 32/2500, or 0.0128.
  • And the probability of getting a bar with no fruit symbols is 128/2500, or 0.0512.

To get the expected value for each combination, you just multiply the probability by the payout:

  • Three fruit symbols is worth 0.0032 X 200, or 0.64.
  • Two fruit symbols play any other symbol is worth 0.0064 X 25, or 0.16.
  • Getting one fruit symbol plus any other two symbols is worth 0.0128 X 5, or 0.064.
  • Getting a bar with no fruit symbols is worth 0.0512 X 1, or 0.0512.

Add all those together, and you get an overall expected return of 0.9152, or 91.52%.

This means the hypothetical slot machine I described has a house edge of 100%, 91.52%, or 8.48%.

But What Does the Casino House Edge Really Mean?

The casino house edge is a statistical prediction of how much you’re going to lose on the action that you place. For example, if you bet $100 on a game with a house edge of 8.48%, you’re expected to lose an average of $8.48.

But this is a statistical average. As you can see in the example above, you can’t lose $8.48 on a $100 bet on this machine. You can lose $100. Or you can win an amount of between $100 and $20,000.

It’s a long-term expected average per bet, what you can expect after thousands of repetitions. This is what the Law of Large Numbers is all about. In the short term, with anything that’s random, you never know what’s going to happen. You might win a lot or lose a lot. On a single spin, you’re looking at the ultimate example of the short term.

West Virginia Slot Machines

But the closer you get to an infinite number of repetitions, the closer your average results will get to the statistical expectation.

At 10 slot machine spins, you’ll almost certainly get closer to that 8.48% expected loss rate. At 100 slot machine spins, the probability of getting close to the statistical expectation goes up even more. And so on at 1,000 spins and 10,000 spins.

How Long Does It Take to Get Into the Long Run With a Slot Machine?

The average slot machine player makes 500 spins per hour. That’s the same thing as 500 bets. Contrast this with the average number of bets per hour at various casino games:

  • Blackjack might result in 60 bets per hour depending on the number of players at the table.
  • Craps might result in 100 rolls per hour, but depending on your betting strategy, you might not be placing a new bet on every roll. If you base it on decisions per hour, you might be looking at just 30 bets per hour.
  • Roulette might result in 60 spins per hour, and if you’re only placing one bet per spin, you’re only looking at 60 bets per hour.

If you notice, the number of bets per hour at a slot machine is greater than the number of bets per hour on any table game by a huge margin. The fastest of these table games is craps, but you’d need to be placing a new bet on every roll of the dice just to make 1/5 of the number of bets you’d make on a slot machine.

What Does This Mean to the Amount of Money You’re Expected to Lose on Slot Machines?

The casinos calculate a game’s predicted win for the casino by multiplying the average hourly action by the game’s house edge. The hourly action is just the product of the average bet size multiplied by the average number of bets you make per hour.

For example, when playing blackjack, the hourly action might be $10 per hand at 60 hands per hour, or $600 per hour in action. If the house edge on the blackjack game is 1%, you’re looking at an average loss of $6/hour. That’s not a bad deal for an evening’s worth of gambling entertainment.

But suppose you’re betting $3 per spin on a slot machine. That means you’re putting $1500 into action per hour. And if you assume a 6% house edge, you’re looking at a predicted $90 per hour loss rate.

That’s a huge difference.

What Happens to Your Average Hourly Loss Rate on Slot Machines When You Start Making “Big” Bets?

Okay, so suppose you decide to cash out your 401k and play the high roller slots at your local casino. Let’s say these games have a max bet of $100. How much money are you expected to lose for an hour of this kind of action?

$100 X 500 spins is $50,000 in action.

With a 6% house edge, your expected loss in an hour of play at this rate is $3000. That’s a lot of money to lose on just an hour of entertainment. Sure, you could get lucky and have a big winning session. But the longer you play, the more likely you are to lose, and the more money you stand to lose during that losing session.

It’s Okay to “Take a Shot”

One of my professional poker mentors explained to me that it’s okay to occasionally ignore strict bankroll management requirements in poker if you want to “take a shot.” The idea is that you’re willing to risk a relatively large amount of money on a big gamble.

Pile of Poker Chips

This doesn’t mean buying into the World Series of Poker every week for $10,000, if that were even possible. It does mean that it’s okay to save $1,000 a month for a year to be able to take a shot at the final table next year.

It’s okay to place a single big bet on a slot machine on the outside chance you might get a win.

Most people, though, treat slot machines like Lay’s potato chips. They can’t eat just one potato chip, and they can’t just make one slot machine spin.

Conclusion

When should you bet big on a slot machine game? The short answer is, almost never. The house edge is too high, and the number of bets you’ll make per hour multiply that amount exponentially. And the more bets you make, the likelier you are to see the statistically expected results.

If you want to bet big on a slot machine, limit yourself to a single big bet. If you’re really aggressive, set some arbitrary number of spins as your target.

I once played a game for $100 per spin for just 10 spins. I won $6,000 that session, so it went okay.

Had I stayed at the machine for a couple of hours, though, I would have almost certainly have given all that back to the casino and then some.