There is a safe way. Never play with emotions or impulse. Never go all in with your total bankroll. Have good money management, split your bankroll and bet with amounts that are 1/15th of your bankroll, that way when you lose you still have many more to place and become even at worst case. Knowledge in what you bet is also needed, bet on things you know like players and many other factors. You only need to win 55% of the time and be at a small profit, over time that adds up. I have bet for 2 years and I am at a small profit of 2 bitcoins, however I have had many risky games parleys of 6 games where only 1 loses, so if I played safer I would be at a bigger profit. Bottom line is you have weeks and months where you lose and weeks when you win, as long as you manage your money good you should be even at worst case.