It would make more sense (to me) to have the opponent's strength plotted relative to mine, rather the absolute values like it is now.
So instead of 1400, 1500, 1600, 1800 etc. have it plotted as -200, -100, 0, +100, +200.
So instead of 1400, 1500, 1600, 1800 etc. have it plotted as -200, -100, 0, +100, +200.