What game had Mij invented?
Mij invented a game using a ping-pong ball and a damaged suitcase. The lid of the suitcase remained at a slope when closed.
In this game, Mij would place the ball on the high end of the suitcase, allowing it to run down the length of it to the other end. He would then dash around to ambush the ball's arrival, crouching and hiding before springing up to take it by surprise. After grabbing it, he would trot back to the high end to start the game all over again.
Explanation
The textbook describes how Mij invented his own game with a ping-pong ball that could keep him engrossed for up to half an hour. He used a damaged suitcase whose lid sloped from one end to the other. Mij discovered that placing the ball on the high end made it run down the suitcase. He would then run to the other end to ambush the ball, grab it by surprise, and carry it back to the top to repeat the process.