Suppose you have a lazy economics prof. He tells you that rather than teaching a proper course and giving out proper grades, he will base your grade on a single choice.
You have two options: alpha and beta. After all students choose, you will be randomly paired with another student in the class.
If you both you and your partner have chosen alpha, you each get a B. If both you and your partner have choosen beta, you each get an A. However, if one of you has chosen alpha and the other has chosen beta, the one who chose alpha gets an A+ and the one who has chosen beta gets a C.
Which do you choose?