I guess that you cannot always win with your martingale strategy because of it still difficult to get this strategies works in a long time no matter you can master the strategies. maybe martingale is work in the short time only and for a long time, I think you need to make another strategy so you can still win in the game. I hope that you can control yourself and not spend too much money if you decide to play in all day long.
Martingale will work if :
1. We have an unlimited balance
2. The casino has no max profit rule, means we can bet with whatever amount we want.
And I guess, those two conditions will be impossible to achieve and that is why I considered martingale isn't the perfect strategy in gambling. It can work if we are lucky enough and know how to stop, otherwise it will fail.