The math is not wrong, the mistake is that the 0.41 are not from higher expected value but from higher investment. The martingale need $32 capital for surviving 5 losses. If you invest the $32 without martingale, you had $6 per trade for surviving 5 losses, so you have 0.6 profit per trade, not 0.41. So, martingale loses even with 55% win rate. laugh