A 10-year-old boy who lost his left arm trained in judo under a sensei who taught him only one move. Over several months of training and competing, the boy was able to win his first two matches and ultimately win the tournament using only that one move. After winning, the boy asked his sensei how he was able to win knowing only one move. The sensei explained that the boy had almost mastered one of the most difficult throws in judo and that the only defense against that move was to grab his left arm, which due to his injury, his opponents could not do.