At which the champion takes something for less than the difference of his score and his opponent\'s, and instead of the game ending on a positive note, it now ends on a downer prove-out where no one cares that the challenger got to 450, because the champ is on 500 and ready to face the devil. Yes, that would be closer still to 100% parity, but it would also make for lousy television.
For posterity I will note that the single-player, general knowledge question format of Play the Percentages absolutely cornholed the returning champion as he would go second in each round, and players were not given equal turns; whoever reached 250 points would win the game.