I used to wrestle inner city kids from the suburbs of Cleveland.
A controlled level playing field does a lot to promote fairness.
But they would try to cheat all the time by putting Sulfa8 on their heads and crap. I would demand that the officials made them go wash that crap out.
One guy got do the match with the sulfa8 on his head after my protests. I head butted him right in the eye coming off a headlock. Whoops! I slipped!