I think the safest method to gamble a bit safe and also not risks too much is by pokerring because you can than really push the luck to a minimum with a good strategy of course.
Some says that if you are good in making analysis while playing poker games you there is a big chances that you can defeat your
opponents but I don't think its true because it is more depending on luck not because how good you are in doing analysis or what etc.
It is true, because poker requires analysis unlike DICE and the other games in gambling, but this doesn't assure you that you could win against your opponents, especially only AI's are the one you are going to compete on the Poker Games here in the online casinos, P2P is really hard to find, but I've read some articles about this, that a gambling site would allow this P2P on playing poker, but I'm not sure if the information is legit though.
If you are playing only against the online gambling site, which is always most of the case, you will eventually lose if you are not smart enough to stop when you need to. The reason is that, online casinos have house edge advantage - which means at the end of the day, they will going to win no matter what.