Can roulette wheels really be biased? I was reading an interesting book the other day, the Secrets of Winning Roulette by Marten Jensen, and it got me wondering about this very topic.

The Secrets of Winning Roulette book (published in 2002 or thereabouts) devotes quite a bit of paper to the thought that biased wheels could exist. I’m not sure on my own views on this. I guess it’s possible that there could be some bias on older technology wheels, although I doubt it is likely on newly engineered wheels which would have higher manufacturing precision.

That said, how would a typical player determine if a particular wheel was biased? According to the book (and I paraphrase), it’s worth showing interest in any wheel where a number has won more than 10 times in 200 spins, and where each of the adjacent numbers to that number are also winning more times than the average. What is the average? Roughly 1 in every 37 or 38 times (depending on the wheel being played – circa 2.63%). So a number which win 10 times in 200 spins is acheiving an average of about 5% (almost double the normal average).

In principle it all sounds great: watch the wheel, find it has bias, bet your chips, and rake in the cash! But it’s not that simple. I think it would take a typical player 3-4 hours to gather their 200-spin data set. However, also according to the book, the player might want to take two or three data sets before risking their money – because the data just collected might have just been a “spike” from standard deviation. To my mind, 600 spins might well take 10 hours or thereabouts to take note of. That seems a lot of time to me, and hardly worthwhile unless the bets the player is going to make are substantial.

More worrying, every casino has surveillence. Surely someone in the pit or in the eye-in-the-sky above would be questioning the intent of a person sitting near the roulette wheels noting their numbers for 10 hours straight? Or am I mistaken?

Whether roulette wheels are biased or not, I still believe there’s no foolproof system to beat them in the long term. There are various tools and software products (for use with online casinos) that might assist short term players – but in the end, the more you play, the more you pay. I wish it was the more you spin, the more you win. Saying that, if you know of a biased wheel near you, do let me know. I’m happy to be proven wrong (after we’ve both made a sackful of cash on that wheel)!