How To Calculate Probability Of Slot Machine Calculation

  • Your chances of winning with slot machines vary from one game to the next. You may first look to a game’s return to player (RTP) to determine your odds. RTP shows how much you can expect to win from a game in the long run. If a slot features 97% RTP, then.
  • The most common type of mechanical slot machine has three reels with twenty symbols on each reel. To calculate the total number of combinations of symbols on this machine, we multiple the number of stops (symbols) on each reel by the number of stops on each of the remaining reels. For a three reel machine with twenty stops per reel, we.

First of all, we must start with the number of possible combinations. In the case of slots, it is relatively simple – just multiply the numbers of symbols on each reel. The oldest slots had, for example, 3 reels with ten different symbols on each. The total number of combinations that could appear on the panel was 1,000 (10 x 10 x 10).

The number of combinations in today’s slots is somewhat higher. If we assume five reels with 30 symbols on each, we get a total of 243,000,000 combinations.

If you want to calculate your chances to win on an online slot machine, all you need is this simple equation:

Roulette and slots cost the player more - house advantages of 5.3% for double-zero roulette and 5% to 10% for slots - while the wheel of fortune feeds the casino near 20% of the wagers, and keno is a veritable casino cash cow with average house advantage close to 30%.

Number of winning combinations / Total number of combinations

To calculate the payout of the slot machine, modify the formula a little:

Σ (winning combination_k * possible yield_k) / (Total number of combinations)

How To Calculate Probability Of Slot Machine Calculations

Let’s analyze a few basic slot machines. For the purposes of our article and in order to simplify the calculation, we will assume that the slot machine has only one payout line and the bet is one coin per round.

Analysis of the simplest slot machine

Let’s go back to the past and assume that the machine only has 3 reels and there is an apple, an orange, a lemon, a banana, a melon and a joker symbol on each. The individual combinations produce these winnings:

  1. Three jokers win 30 coins
  2. Any three fruits win 10 coins
  3. Two jokers win 4 coins
  4. One joker wins 1 coin

The total number of combinations is 216 (6 x 6 x 6).

Total number of winning combinations:

  1. In the first case there is only one winning combination (1 x 1 x 1 = 1)
  2. In the second case we have 5 winning combinations (3 times apple or 3 times orange or 3 times lemon, …) (1 x 1 x 1) x 5 = 5
  3. The joker may appear on any two reels. The calculation is as follows: 1 x 1 x 5 + 1 x 5 x 1 + 5 x 1 x 1 = 15
  4. The joker may appear on any reel. 1 × 5 × 5 + 5 × 1 × 5 + 5 × 5 × 1 = 75

Our simplified model thus contains 1 + 5 + 15 + 75 = 96 winning combinations. The table below shows the probability of a payout.

Winning combinationNumber of combinationsWinningReturns for 1 coinChance to win
3 jokers1303013.953%
Any fruit5105023.256%
2 jokers1546027.907%
1 joker7517534.884%
Total96215
% for the winning combination44.444%Payouts99.537%
How To Calculate Probability Of Slot Machine Calculation

Calculation of payouts according to the formula

Σ (winning combination_k * possible yield_k) / (Total number of combinations)

(1 × 30 + 5 × 50 + 15 × 4 + 75 × 1)/(6 × 6 × 6) = 215/216 ≈ 0.99537

Probability

In this case, the slot machine has a payout ratio of 99.53%, which is very nice, but in a real casino, you will not find the same results. The average returns of slots online casinos will be between 94% and 98%.

The table also clearly shows how single coin wins affect payouts. If the win of each combination were equal to one coin, the winning ratio would drop to 44.4%. And that’s a very small number.

Analysis of a more complicated slot

Because the previous example was too distant from reality, let’s show you another example with higher numbers. To simplify, let’s assume again that there is only one payline, the slot machine has 3 reels and a total of 6 symbols that can appear on the panel:

How
SymbolReel 1Reel 2Reel 3
BAR111
SEVEN311
Cherry433
Orange566
Banana566
Lemon566
Total232323

The total number of combinations is 23 x 23 x 23 = 12,167.

Winning combinations with single coin returns:

  1. 3x BAR, win 60 coins, number of combinations 1
  2. 3x SEVEN, win 40 coins, number of combinations 3 x 1 x 1 = 3
  3. 3x Cherry, win 20 coins, number of combinations 4 x 3 x 3 = 36
  4. 3x Other fruit, win 10 coins, number of combinations (5 x 6 x 6) x 3 = 540
  5. Cherry on two reels, win 4 coins, number of combinations 651
  6. Cherry on one reel, win 1 coin, number of winning combinations 3,880

Calculation for no. 5:

Cherry, Cherry, Other: 4 x 3 x (23 – 3) = 240

Cherry, Other, Cherry: 4 x (23 – 3) x 3 = 240

Other, Cherry, Cherry: (23 – 4) x 3 x 3 = 171

Calculation for no. 6:

First reel: 4 x 20 x 20 = 1,600

How To Calculate Probability Distribution

Second reel 19 x 3 x 20 = 1,120

Third reel 19 x 20 x 3 = 1,120

How To Calculate Probability X Equal To

The following table shows the amount of payout and the chance of winning for the individual combinations.

How To Calculate Probability Statistics

Winning combinationNumber of combinationsWinningReturns for 1 coinChance to win
3x BAR160600.495%
3x SEVEN3401200.989%
3x Cherry36207205.934%
3x Other fruit540105,40044.507%
2x Cherry65131,93516.097%
1x Cherry3,88013,88031.979%
Total5,11112,133
% of winning combinations42.007%Payout99.721%

How To Calculate Probability Youtube

As you can see, the payout ratio is very high again at 99.721% (12,133 / 12,161). If the slot were to pay a straight win for each winning combination in the amount of 1 coin, the payout ratio would be down to 42,007%.