Couple days ago I spent 12 mBTC just for fun, and this fuckin martingale didn't work. My first bet with 0.1 mBTC was under 43, red. next five bets under 43 and each time was over 60. my 12 mBTC was gone in 30 seconds. That is martingale!
Been using martingale before but I stop it already before I lose a big amount due to some learning from the experience of others who busted their bankroll because of this method.
How about trying it in sports betting or whatever games where house edge is not present.
In sports betting it is good for sure you will earn as i've experience.