Pranoy gave Niloy the following challenge: "If you sit down in that chair, I bet I can make you get out of it before I run around the chair three times," he said.
"Aw, that's not fair," Niloy said.
"You'll just pick me with a pin or something."
"Nope," Pranoy said.
"I won't touch you, either directly or with any object. If you get out of the chair, it'll be your own choice."
Niloy thought, accepted the challenge, and lo and behold, Pranoy won the bet.
How did he do it?