I think Martingale sucks in sport betting.

Firstly you need a team which is quoted at a 2.0 odd all the time. cause on a good team it doesn't work. lets say one week Barca looses and second week you place a double amount bet on the next week on Barca at a 1.3 odd then you still do not cover your previous loss.

If you want to apply Martingale on a good team then you can better bet on them to loose. The very good teams will loose a game eventually and mostly those odds can go up to 10+. So if you apply martingale on for example Barcelona to loose you will eventually win. And if you are lucky they loose at home against a very weak opponent then you can make a nice cash.