It depends on the situation because most of the cases the chances of losing is high and people think they are gambling expert it will lead them to invest higher amounts in gambling. So don't consider you are gambling expert if you think so then you will start losing more money.
Losing will always have a higher percentage else how will the gambling or casinos be surviving if people start winning it. If owners do not make any money then they wont be running this quite simple. Also their may be people who could be expert in some of the games like cards being the prominent among it rest of them are luck based mostly.