Depends on his stack I think. You shouldnt stick to Martingale if your bankroll isnt huge or you may get wracked in no matter of time. Imagine he starts with 1 BTC and has a loss streak for eg 5 games. He would have lost 1 + 2 + 4 + 8 + 16 BTC at the blink of an eye.
You shouldn't stick to martingale unless your bankroll is infinite.
I repeat, INFINITE.
No matter what the amount is, 1 or 100 or even 1000+, sooner or later there will be a round where you'll have to go all in to save your initial bet which is probably a few thousand sats. If it is lower, it is even worse.
True that. There was a time I started with 4-digits Sats and the whole thing ended up nomming almost 1 BTC. I was on a loss streak of almost 15 rounds!