[PavleMiha]

I think the other posters mean sports betting and other betting markets when they say "betting" not just casino games where, as you rightly say, there's no way of making money.

In sports betting markets it is theoretically possible to make money, but very hard.

[anfractuosity]

Yeah I was thinking of sports betting, however I guess even in casinos you can do card counting or apply the laws of physics to roulette wheels.

https://en.wikipedia.org/wiki/J._Doyne_Farmer#Beating_roulet... (although the roulette example could be classed as cheating ;)