only martingale is the best strategy for every single gambling game
i would agree with that if you have infinite amount of money and time ,so that you can double every bet on loss and eventually recover every loss.
otherwise your logic fail's.
I dont think his logic fails. It is correct I think for every single game. I think what he mean as a single game is that , 1 single win. So each lost will double up your wager and eventually you win unless you are very unlucky and hit very bad streak