I've had plenty of success with the Martingale strategy on the Auto-bet option on Multiply BTC. Set ON WIN to Return to Base Bet and ON LOSE to Increase Bet By 50% (although martingale requires doubling) and start. Unless you're VERY unlucky, this will garner you consistent gains. But here's something you have to take into account: have atleast a 100,000 satoshi balance, and start betting with 5-10 satoshi per bet to minimize the chance of losing everything at once.