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Slot Machines Odds and Winning Chances

To get familiar with the slot machines odds and probabilities it is important to define the difference between the winning odds for classical mechanical reel slots and advanced video slots using Random Number Generator.

Reel slot machines odds

Slot machines odds for classic reel slot machines are basically defined by certain mechanical devices that control the work of reel-type slots. Each reel of the slot machine has a set of symbols imprinted on it. The chances of hitting a particular symbol are calculated through dividing it by the total number of symbols on each reel.

For example: slot machine odds for hitting one symbol on a standard three-reel machine with ten symbols on each reel are 1 divided by 10, which is actually 9 to 1. The odds of hitting two identical symbols on two reels are 1/10 multiplied by 1/10, which is 1/100, or 99 to 1. The odds of hitting three identical symbols on three reels are respectively 1/1,000, or 999 to 1.

To calculate the payout percentages for reel slots we add the payout percentage for each bet, actual payout for each bet and the probability for winning the bet.

Video slots odds

Modern video slot machines that have almost completely replaced the classic mechanical models offer totally different slot machines odds of winning:

  • Actual reels have turned into graphically simulated reels on video screens and physical stops on the reels have been replaced by the slots Random Number Generator.
  • While a physical reel of the mechanical slot machine can accommodate up to 20 symbols on three reels (which is the optimal number of reels), there are no limits for the number of reels and symbols with video slot machines. An advanced video slot may offer up to 100 symbols on each reel and 5 or even 7 reels in total.
  • The Random Number Generator installed in the video slot machine is pre-programmed to select different combinations for certain symbols each time, irrespective of the actual number of symbols on the reels. For example, a classical model may have a cherry symbol come out once in 10 symbols, but with the RNG the slot machines odds for hitting a cherry may be once in every 20 spins of the reels.

This means that by use of the Random Number Generator slot machines can be programmed to hit less likely symbols combinations. The less likely the combination is, the more it actually pays out. For example, the slot machines odds to win progressive jackpot with a combination of seven symbols could have been improbable without the RNG that can be programmed to make this combination likely.