class Juego(models.Model):
 player_a = User()
 player_b = User()

     def winner(self):
        winner = cache.get('%s_winner' % self.id)
        if winner:
            return winner

        plyA_votes = self.player_a.received_votes.filter(battle=self).count()
        plyB_votes = self.player_b.received_votes.filter(battle=self).count()
        if plyA_votes > plyB_votes:
            cache.set('%s_loser' % self.id, self.player_b)
            return self.player_a
        elif plyB_votes > plyA_votes:
            cache.set('%s_loser' % self.id, self.player_a)
            return self.player_b
        return None

class Voto(models.Model):
 by = User()
 to = User()
 juego = Juego()