Recently I saw someone playing BJ using martingale on betting. For two hours, the guy's chips kept piling up. The pit boss kept changing dealers on my table. At one point, the casino have five new dealers in less than five minutes. Some of them just burned a card and dealt one hand.

After two hours, this guy had a 8 straight losses. It wiped out all his chips and actually he need to open his wallet for his last bet. And he got wiped out only three minutes after the amount of his chips peaked.

What amazed me more is that the casino thinks this guy is a threat and they need DO SOMETHING, like change dealers again and again. He only played Basic Strategy. They should know better that martingale betting won't work. Once you lost the table maximum bet, you are out.