Hi,
Martingale is always losing strategy,
even if you wait before play.

You can test it here where you can crash any strategy you want with a million bets in 0.5 seconds:
https://www.bitso.me/hi-lo-calc.php

On top, use strategy=1, down set "min losses" at 1, set the margin you prefer, then in "tot rolls" set 1000000