The more you play, the more you're likely to lose them all. Don't play BTC gambling games to try and make you rick or "turn 0.24 btc into 0.25 btc for a nice number, they're not worth it. Only gamble if you want to lose your coins.
The validity of your statement depends entirely on where and what you play, and if it's a game of skill (say, poker), how skilled you are at it. For example, there are raffles over at
BitDraw that no one is entering. If a single person enters, they are guaranteed to win, and will win more than twice what they paid for the raffle ticket (prize amount goes up as people buy tickets).
I've also personally made money playing BlackJack over at
BitZino, but that's because I know how to play BlackJack properly (: