I think Andres suggested that lower battle ratings can defeat higher battle ratings is possibly due to percentage.
Eg: Equal % = 50% Chance for each person
Rating=-0 opponent= 50% ? Player X = 5 Player Y = 5
Rating=-2 opponent= 40%? Player X = 4 Player Y= 6
Rating =-4 Opponent= 30%? Player X = 3 Player Y = 7
Rating = -7 Opponent = 15%? Player X = 2 Player Y = 9
Rating = -9 Opponent = 10%? Player X = 1 Player Y = 10
Rating = -10 Opponent = 5%? Player X = 0 Player Y = 10
Rating= -11 Opponent = 0%? Player X = -1 Player Y = 10
I presume this to be a rough idea of how things are probably going for duels.
Dunno who to vote.

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