After several years I just re-established contact with a BJ-playing colleague. A few years ago he was playing in a UK provincial casino when he noticed on a roulette results “tree” that a certain number had hit 6 times in 15. He thought it looked interesting so began writing numbers. This wheel and several others of the same make turned out to be massively-biased and for the next 3 years they played it until the casino removed the wheels. This was about 3 years ago.

The amount they eventually won was a 6-figure number of which about half went on wages, etc. Not huge but then they were not playing big, which is probably why the game lasted so long. He just sent me the records of the best wheel –– in 27,000 spins the best numbers hit 938, 885, 823, 814, 812, 794, 783. In total there were 13 winning numbers, some of them marginal.

The most interesting feature is that those 7 best numbers were all black. In fact if they had only played black (even chances) they would have won 3.2% of turnover. Surely this is the holy grail of roulette?
Have you come across anything like this before? And what could have caused such a massive bias?

They didn’t take into consideration any variables like rotor speed, ball size, spin direction, nothing at all.
Thanks for a nice series of articles.