I've heard people argue about this or that strategy but it has not helped them for long, as at times, someone may be lucky and a certain strategy worked well for a limited time, and might now think it was their strategy that worked, why can't the strategy work after then? We should not deceive ourselves, and no matter the slot games we play, we should always keep the risk minimal and make sure we know when to call it a quit. And specifically, I don't see the martingale games as one of the conservative ways to achieve that.
Even if they win with those strategy for once, they can't repeat the same thing on multiple occasions because it is not designed to work that way and that is where the loses will always come, because some of those that get such strategy may even go as far as borrowing money to stake with with the hope that when the game comes that will have enough money to pay back Their loans and still have some profits left, but always opposite is the case for them, I use to know a guy here in the forum that took a loan in bitcoin to gamble with, when he took the loan, the dollar equivalent of the amount was around $120 in bitcoin, and he lost all the money, and when he want to pay back, the price of bitcoin have increased at that moment and he have to pay higher in debt when calculated and converted to dollars from bitcoin, so strategy is a sure way to get into troubles with your bets.