score:4
It was Sun Tzu, in the Art of War, that advocated putting soldiers in death ground to make them fight.
"Put them in a spot where they have no place to go, and they will die before fleeing. If they are to die there, what can they not do? Warriors exert their full strength. When warriors are in great danger, then they have no fear. When there is nowhere to go they are firm, when they are deeply involved they stick to it. If they have no choice, they will fight."
That, in essence is what Fermor did at Zorndorf. He didn't exactly defeat the Prussians, but he inflicted a "Pyrrhic victory" that was only slightly less costly than their defeat at e.g. Kolin.
An American commander, Daniel Morgan, did a similar thing during the American Revolution at the Battle of Cowpens. Facing a young, aggressive British commander, he placed his army with its back to the Broad River. It was a battle plan that basically insured the destruction of either the American or British army (the British lost).
Russian soldiers weren't necessarily braver than others, but their commanders were more likely to put them in "death ground."