Monday, January 11, 2010

More on gambling and random seeds

I always appreciate it when people write in with questions about something I've posted before. Gives me an excuse to keep this blog at least somewhat active.

Joe in Illinois writes:

Enjoyed reading your article on google regarding how to set a seed and randomness. Would different seeds contain different overall results. For example, some people would argue that a simple Jacks or Better video poker game returning 99.54% (in the long run, whatever that is) is still not purely random because the maker must still set this % ( over time), So would/could some seeds produce more winning combinations, maybe with fewer overall winning numbers in the seed. Players would not recognize one seed starting or ending. The next seed would/could have say, only 16% of winning combinations. Some people are overly concerned with this RNG, I say it's just doing its job, running constantly. But I also think that the player should hope for a positive seed, along with some luck and knowledge.

The short answer is, yes, different random seeds would lead to better or worse luck. But in the long run, with a good random algorithm, it wouldn't matter to you. Hoping for a "good" string of numbers coming from the RNG makes neither more nor less sense than hoping for good luck when you sit down at a physical card table.

Look at it this way. If you take a video recording of your session at a poker game, obviously you'll draw more good hands than bad hands sometimes. If you took different videos on successive days, and later you compared the tapes, then you could say "Oh look: on day one I had a lucky streak, and on day two I had an unlucky streak." But that's just the way random numbers actually behave: it's a rare string of randoms that don't show signs of patterns that appear meaningful but aren't.

Since the nature of a correctly designed random number generator is to simulate real random numbers, of course an RNG will create those same apparent patterns. But as long as there is no way for you to reverse engineer the algorithm or figure out what the seed actually was, hoping for a certain pattern is not much more than superstition.

Another interesting thing to note is that the nature of probability is that the larger your sample set is, the more likely it is to confirm to the expected distribution. In other words, if you only play three games in a row, it's not entirely unlikely that you could get a lucky streak and win all three games. Of course, it's slightly more likely that you would lose all three games; but still, if you believe in luck, betting a lot on a small number of hands makes some sense. The longer you play, though, the less the game's outcome will look like a sequence of wild streaks, and the more it will look like a typical bell curve distribution of some sort.

Thus, if you play 5000 hands of video poker, you are almost guaranteed to gradually lose money at the expected rate, as very lucky or very unlucky streaks will tend to cancel each other out.

1 comment:

  1. This reminds my of one of my early adventures in coding as a kid: I made a random 2D6 roller and let it run for days to prove to myself that statistical methods do indeed match reality. Guess what everyone - statistics is right about probabilities!

    As for gambling using computer generated random number generators: yep, most people don't play a single hand, so it evens out. My first job was cutting code for One-armed-bandits, and we had to make sure that people lost around 85% of the time (yes, there are laws for the statistical likelihood of winning and losing) - go figure.