One Arm Fighting

A little boy once lost his left arm in an accident, but still wanted to learn judo. He finally found a
judo master, but the master would only teach him one move and one move only.

So he drills endlessly in that one move. 3 years later, his master tells him, "now you are ready for competition."
In the preliminary rounds, he won easily using only that one move. As he moved through the octos, quarters, and semifinals, that one move also allowed him to win effortlessly.

Finally, it was the final match. His opponent was much bigger and stronger and looked a lot healthier.

Yet, with that one move, the boy defeated him and became champion.On the way back, the boy asked his master, "How was I able to win with only one technique?"The master replied,
"Two reasons.
1. That technique is one of the most difficult to master.
2. To my knowledge, the only counter to that technique is to grab the opponent's left arm."