Weakness or strength...

A young boy had lost his left arm in a devastating accident. But the boy had a great desire to learn judo, inspite of his handicap.

His parents arranged for a judo teacher. The boy started his training with complete belief in his teacher.

Almost three months had passed since the boy had started training. But to his surprise, he had learnt only one move. With some reservations, but believing in his teacher, he continued.

Now, six months had already passed, and he was still fixed on only one move. With some anxiety, he approached his teacher one day and asked, " Sensei, shouldn't I be learning some more moves?". The teacher answered with a perky smile in his voice," This move is the only one you'll ever need to know!!"

Somewhat confused but still believing in his teacher he continued. The teacher enrolled him in a competition the next month.

To his amazement, the boy had easily won his initial matches. In the advanced rounds the boy met a stronger opponent, but he deftly used his pne move to pin him down.
To his utter surprise, the boy was now in the finals. This time the opponent was stronger, bigger and more experienced. For sometime the boy appeared to be overmatched. Fearing that the boy would get hurt, the referee called Timeout and opined to suspend the match. But the teacher persuaded him to continue. Soon after, the opponent got frustated and dropped his guard, and the boy used his move to win the match. He was now the champion.

On their way home, as the boy and the teacher were reviewing each match, th boy summoned up courage to ask the teacher," Sensei, how did I win with only one move?"
The teacher answered," first of all, you have mastered one of the most difficult throws of all judo. And second, the only defence to that move is for your opponent to grab your left arm!"

Weakness or Strength. You name it???