How to Win Casino Games and Influence Probabilities

Closeup of Hand on Slot Machine With a Roulette Table Background

Anyone can win a casino game. All you need to do to win is to play. The trick is making a profit.

After all, if you stick with the even money bets at the roulette table, you’ll win 47.37% of the time.

But with a winning percentage like that, you’re guaranteed to lose money over time.

In fact, if you play long enough, you’ll lose all your money just because of the math.

Here’s how to win casino games and influence probabilities like a champ.

You can’t influence anything you don’t understand. Well, you can, but you won’t know if you’ve influenced it in one direction or the other, and you won’t be able to tell by how much, either.

This is why a basic understanding of probability is essential for anyone who wants to win casino games and influence probabilities.

The first thing to understand about probability is that it’s how you measure how likely something is to happen. A probability is just a ratio comparing the number of ways something can happen versus the number of ways it can’t happen.

For example, the probability of getting heads when you flip a normal coin is 1/2. You have two total possibilities, both of which are equally likely, and only one of them is the “winning” possibility.

If you convert that fraction to odds format, you’re looking at one to one odds, or “even” odds.

This becomes important in gambling because you can compare payout odds to the odds of winning to determine how much of an edge the casino (or you) have.

Understanding the Concept of the Casino House Edge

The casino house edge is a statistical measurement of the difference between the odds of winning and the payout odds. Casinos always pay out at odds lower than the odds of winning, and that’s how they win in the long run. The bigger the difference is, the faster they win your money.

Roulette is my favorite illustration. Suppose you bet on red. What’s the probability of winning that bet?

You have 18 red numbers on a roulette wheel, 18 black numbers, and two green numbers.

So, you have 18 ways to win versus 20 ways to lose.

Closeup of a Single Zero Roulette Wheel

The bet pays off at even money, one to one odds, even though the odds of winning one to 0.9.

The difference is the casino house edge.

Suppose you bet $100 on 38 spins of the wheel, and you see statistically perfect results. You’ll win $1800 and lose $2000 for a net loss of $200.

Average that out over 38 spins, and you’ll get an average loss per spin of $5.26.

That’s 5.26% of the $100 you bet each time, which means the house edge is 5.26%.

You can think of the house edge as being like a tax that the casino charges you to play the game, but it’s a tax that’s applied randomly in such a manner that it only shows up over the long run.

Choose One Bet Over Another Based on the Casino House Edge

Generally, a bet with a higher house edge is worse than a bet with a lower house edge.

This seems obvious, but in case you’re missing the point, let’s compare the house edge of two games – blackjack and roulette.

If you play blackjack for real money with perfect strategy, the house edge is only 0.5%. (I’m assuming a reasonably good set of rules and playing conditions.)

This means that when you bet $100 on a hand of blackjack, your projected loss is only 50 cents.

But if you bet $100 on a spin of the roulette wheel, your projected loss is $5.26.

One game costs 10X as much as the other game – at least as measured on a per bet basis.

Other factors matter, too, like volatility and rate of play, but assuming those are the same, you should always go for the bet with the lowest house edge you can find.

Factors That Affect How Much You Can Expect to Win or Lose

Volatility just represents how big the swings are between losing and winning.

Some games have different volatilities depending on which bets you’re placing. For example, in roulette, even-money bets have low volatility. You’ll lose a little more than half the time, and you’ll win a little less than half the time, and you’ll always be going up or down a single betting unit.

But if you bet on a single number at roulette, you’re going to see more volatile results. You’ll lose most of the time, but when you do win, you’ll see a bigger win. A single number bet in roulette only wins once every 38 spins on average, but when it does, you win 35 to one on your money.

This same concept applies to other games, but it gets more complex. For example, a slot machine that pays off a 1000 for one jackpot once every 1500 spins is even more volatile, but it might be less volatile based on how many smaller wins you get along the way.

The other factor to think about is how much money you’re putting into action per hour.

Slot Machines at Harrah's Reno

When you’re playing blackjack at a table with three other people, you’re probably going to see 100 hands per hour. If you’re betting $5 per hand, you’re putting $500 per hour into action. This means you’re looking at an average projected loss per hour of $2.50.

If you’re playing roulette at a busy table, you might only see 30 spins of the wheel per hour. If you’re betting $5 per spin, you’re only putting $150 per hour into action. Even though you’re going to lose 5.26% of that, or $7.89, you’re not losing 10X what you’d lose per hour playing blackjack.

The difference is the rate of play.

This, by the way, is one of the reasons slot machines are so profitable for the casino and such an awful bet for the casino gambler. An average slot machine player spins the reels 500 to 600 times per hour.

Even if that slot machine gambler is only betting $1 per spin, she’s putting as much money into action per hour as the blackjack player in the previous example.

And she’s facing a house edge of at least 5% and maybe as much as 25%.

Flip the Odds in Your Favor

If casino games sound hopeless right now, I’ve done a good job explaining how they work. And you’ve done a good job of understanding how they work.

But fear not.

There’s hope.

You can find techniques and strategies that will get you an edge over the casino. These are called “advantage gambling techniques.”

The most famous advantage gambling technique is probably card counting in blackjack. It’s easier than you think, too.

Some people think you might have to memorize which cards have already been played and extrapolate what’s still in the deck to count cards, but the reality is far simpler.

When you’re counting cards in blackjack, you’re just tracking and estimating the ratio of high cards (aces and tens) to low cards in the deck. The high cards are advantageous to the player because they increase your probability of getting a “natural” or “blackjack,” which pays off at three to two odds.

Closeup of an Ace and King Blackjack

In other words, if you bet $100 and get a two-card hand worth 21 points, you win $150 instead of $100.

With proportionally more aces and tens in the deck, your probability of getting such a hand goes up.

If you raise your bets in proportion to how much your advantage has grown, you can get a small edge over the casino.

A good card counter might have an edge of 1% over the casino, which doesn’t sound like much, but if you’re betting enough over a long period, it adds up fast.

For example, if you’re betting $100 per hand on average, you’re looking at winning a dollar per hand.

If you’re at a table where you’re getting 100 hands per hour, you’re looking at averaging $100 an hour in winnings.

Of course, you need a bankroll large enough to withstand any possible losing streaks, but you can get an edge at blackjack.

Gaining an Edge Over Other Casino Games

Counting cards in blackjack is only one example of advantage gambling techniques. It’s beyond the scope of a single blog post to list all possible ways to win casino games and influence probabilities.

Some topics that might warrant further examination on your part, though, might include dice control in craps or edge sorting in baccarat or blackjack. Dealer tells is another way of getting an edge at blackjack. You might even still be able to find a biased roulette wheel.


For the most part, the average gambler will always lose in the long run.

But you should strive to be above average.

If you do the right things with the right mindset – which includes an understanding of the math – you can win casino games and influence probabilities.