Reel Slot machine

In 1984 Inge Telnaes received a patent for a device titled, "Electronic Gaming Device Utilizing a Random Number Generator for Selecting the Reel Stop Positions." International Gaming Technology IGT bought the Telnaes patent and now all slot manufacturers using what has come to be known as Talneas mapping or reel mapping must license the patent from IGT. This device allowed for the creation of what we call the virtual reel.

While a physical reel may have 22 symbols of stops on it a virtual reel can have 32 up to 256 or even virtual stops. The virtual stops are assigned to one of the symbols on the physical reel. Here are the possible outcomes for different numbers of virtual stops.

Stops Outcomes

Look at this example for a machine that has 32 stops on each reel. The total combinations are 32, 768. Listed below is the payouts and number of occurances out of 32, 768

Pay table is:

Symbol Pays Occurrences $Payout

3 Sevens 250 30 7, 500

3 Bars 75 80 6, 000

3 Cherries 12 12 144

Any 2 cherries 8 476 3, 808

Any Cherry 2 6180 12, 360

Total wins $29, 812

Total bets $32, 768

Return 90.979%

Here are the symbols on each reel.

Symbols Reel 1 Reel 2 Reel 3

3 Sevens 5 2 3

3 Bars 5 4 4

Cherries 2 3 2

Blanks 20 20 23

Now if you were to change the number of bars on reel 3 from 4 to 5 the return would increase to 95.577%.

If you decrease the number to 2 the payback would be reduced to 81.824%

If you changed the cherries on the first reel from 2 to 3 the payback would increase to 99.072

This example shows you how adjusting the symbols can affect the return of the machine.