I'm reluctant to play chess against my oldest son, Jonathon. He's 15 and in the past few years has gotten really good. I've taught my three sons to play chess, and I'll never forget teaching the youngest, Robby, 7. When Robby was about five, I was showing him how to castle. Then, a while later, I decided to review with him. "Robby, what do you call it when you switch the king and rook?" I asked.
Robby thought for a few moments and then replied, "Stupid?"
Robby also has this fool-proof way of winning against Dad at chess. Once I've cleared the board of all but two of his pieces, he will then insist that he and I switch sides. Now that I have two pieces to his multiple ones, he is almost certainly guaranteed victory.