Well martingale is always bad. No matter what. It´s just a mathematical fact. Even with a 70% SR a 6-8 or even worse run of consecutive losses will come sooner or later and kill the bank. I don´t know why sugarman does use martingale if he has such high number of winners. I have a sportsbetting background and one thing´s for sure. I martingale does not make a losing system win but makes a winning system lose.