Why are Random Number Generators such a big issue for online casinos? Well did you know that computers can't generate truly random numbers.
Part 1 - Random Online Casinos
In order for a computer to arrive at a number, you must tell it exactly how to arrive at that number. In doing so, you can give the computer other numbers, operators (addition, subtraction, multiplication, etc), and formulas. For example; you could tell the computer to start with the number 2, perform a torourous set of operations on it, and it would give you the result (lets say 25). No matter how complicated the instructions you gave the computer, every time you tell it to start with 2 it will always give you 25 back. Obviously in order for online casinos to simulate blackjack (or any other casino game) they must have some way of making different combinations of cards come up each time you play.
How Do Random Number Generators Work?
The only way to get a different result from the computer (still following the 2 & 25 example) is to tell it to start it with a different number. This is preceisely what (pseudo) random number generators do. Instead of telling the computer to start with 2 the RNG might tell the computer to check your computer's clock and use whatever number the second hand is at. This would lead to 60 different possible outcomes (there are 60 different numbers the second hand might be at). This is certainly better than nothing, but not something you'd be able to base an online casino off of. Players would quickly learn that hitting deal at just the right time would always net them a winning hand.
Another method might be to use a number like Pi (3.1415926535897932384626433832795028841971...). Pi is an example of an "irrational" number. This means if you were to write out say the first 1,000,000 digits of Pi you would not find any repeating pattern in the digits. In fact, no matter how many digits of Pi you wrote out the series would never begin to repeat itself. Using an efficient algorithm a computer can crank out the first billion digits of Pi in very little time. Going through the first billion digits of Pi would be a great way to generate random numbers. Unfortunately this plan would fail for an online casino if one of the players ever found out about it. It might take the player a while to figure out the formula for how the digits taken from Pi were used to determine the cards on his screen, but as soon as he did he'd be able to predict future cards and have a huge advantage over the house! Another way it might fail would be if the digits of Pi just happened run in such a way that they gave the player more winning hands than usual.
The actual method used to calculate pseudo random numbers is sort of a combination of these two methods. First a "seed" is generated by checking the computer's clock, or some other number the computer has access to that is constantly changing. This seed is then used to pick a point in the number sequence to jump in at. For example if the seed was 624,053 the RNG might jump to the 624,053th digit of Pi and begin using numbers from this point on. Even if one of the players knew his BJ hands were somehow related to the digits of Pi it would be more difficult to find how they were related if he had no idea where in the sequence he was.
So Is Pi Commonly Used To Generate Random Numbers?
I don't believe so. In fact it's not very convenient for a computer to have to keep track of a billion different numbers just to generate pseudo random numbers. Instead what usually happens is that a complicated formula is used to calculate a "random" number from the initial seed. This "random" number is then plugged right back into the same formula (as if it were the seed) to generate another "random" number. This second "random" number is also put through the same formula to generate a third "random" number. This process is repeated every time another "random" number is desired. How well this process works depends on the function used. If a poor function is used you might see a sequence like:
0.99743, 0.65031, 0.10550, ....(skip 1,000 numbers)..., 0.96523, 0.65031
What wrong with this sequence is that one of the numbers has repeated. Since the next random number is determined by the last number generated the next number in the sequence above would have to be 0.10550. Then after another 1,002 numbers the cycle would repeat itself again. Repeating cycles are a bad thing because an alert player might be able to use it to predict the outcome of his bets, or even worse the 1,000 blackjack cards corresponding to these numbers might lead to a larger percentage of hands in which the player wins than usual. There are a lot of other things that can go wrong with these pseudo random number generating functions, but they all lead to the same problems:
- The player is able to predict the sequence, or
- The sequences tend to favor the player or the house
Go to page 2 of 2: Random Casinos.