A shogun needed a warrior to defend his home and protect his family when the Shogun was away.
He narrowed his selection to three swordsmen and devised a means to determine who would be the best.
The Shogun instructed the swordsmen to wait in a guesthouse until each was called to the main house. He instructed a servant to stand behind the door in the main house and strike the swordsmen over the head with a stick as they walked in.
The first swordsman was called to the house, walked through the door and was struck over the head by the servant
The second swordsman was called to the house, walked through the door and blocked the stick and knocked the servant down.
The third swordsman was called to the house and told the servant to come out from behind the door.
The servant asked the Shogun which of the swordsmen he had decided on.
The Shogun said “I chose the swordsman who told you to come out from behind the door”.