this is the article that i readed.
http://theconversation.com/can-maths-help-you-win-at-roulette-69440
People can do some calculations while playing gambling, for example in roulette game they can see how many rounds the ball will run usually and what is the previous number and they can calculate next what number will come. This is all just assumptions there is no guarantee that is why they will put multiple bets. This is what I know about this calculation in gambling others what they do I don't know.
You can't just calculate based on how many rounds in previous round it was turned because it also depends on how fast it was turned and that speed I don't think people can guess it. I don't think this game you can guess by any kind of calculation and you will get results just based on your luck. In card games and sports betting these calculations may help some extent but no guaranty that you will win your bet.