Once upon a time, there was a kingdom of an old king with two sons.
The kingdom was surrounded with hostile neighbor countries. Therefore, there had always been wars one after another. Everytime there was one, the two princes fought with enemies vigorously to protect the kingdom. The king were proud of them. He announced that when he died whichever had killed more enemies would be crowned king.
The first prince always fought with one sword on his hand and one shield on another. Meanwhile, the second prince always fought with two swords on his hands. Therefore, in most battles, the second prince killed more enemies.
However, in one big war, the battle took too prolonged. Both of them were too exhausted. The first prince protected himself well since he had one shield, whereas the second prince had a hard time protected himself since he didn't have any protection. When the war were over, the second prince was killed, while the first prince had survived.
So, despite the fact that the second prince killed more enemies, the first prince was crowned king because he had better protection and therefore survived the longest battle.