Looking at this photo which was posted yesterday, it doesn't look like a very smart way of gambling. He started at a base bet of 0.08 BTC and using payout 5.00x, and on every loss he kept doing regular martingale.
But since his wins have less than a 20% chance of every roll, then its not uncommon for him to run into a losing streak of 50 losses in a row. If he got 50 losses in a row, he would need the 50th bet to have a value of 88 Million BTC for him to be able to stay in the game, which is far higher than the max bet amount.
Sometimes I think that people who perform martingale do not bother to do the maths before starting. I'll try to do my best to explain how big your losses might be with the martingale strategy.
Even if your base bet is just 1 Satoshi your 50th bet would be over 11 Million BTC. If the base bet is 0.08 BTC then after 49 losses in a raw you'll need over 45 Trilllion BTC to make the next bet.
So be careful with that martingale thing, guys. )
I do believe big gambler like him knows the worst scenario of martingale, and I believe he has set his bankroll wisely before starting martingale. Means that he is spending money that he can afford to lose.
Luckily he hit big after some rolls, but I'm not really sure what he did after that hit. Whether he stop and withdraw or started it again for more profit.