mostly poker players.It is a game where you choose to bet or not,depending on how strong your hand is.All the other games have odds that favour the casino.Therefore you will always loose in the long run.
If you are disciplined and willing to learn than you can definitely make money from playing poker.Alongside discipline you have to be good at managing your bankroll.For instance if you have $500,You should be playing with $20-$50 at every table you play.Once you build your bankroll and poker skills you can move to higher stakes.