Liberator said:
I was just showing that battles can be won with luck.
Well battles can be won with luck, yes, but good generals do not depend on luck. A better example of your example is:
A huge army surrounds a city, the city is outnumbered by a whole lot and have no way of manning the walls sufficiently, so the city's general ordered all the gates to be opened, with only old men sweeping the way by the gate, and the general plays an instrument on the city walls, infront of the enemy army formations. The enemy sees this, and thinks, hm, they are letting us into the city. No, it must be a trap. And the besieging army retreats. Luck? No. Strategy my friend, the city's general, Zhu Ge Liang, knew the besieging army's general's personality pretty well. He also knew that the enemy general is always very suspicious of things. So he knew if he made things look suspicious enough, the enemy will think it's a trap and retreat.
After 2 days the besieging army's general realized he was fooled and attacked the city again. But the city has been abandoned. No one was inside but civilians.