The secret: guess the middle

The fastest way to find a number from 1 to 100 is to always guess the middle of what is left: 50, then 25 or 75, and so on. Each guess throws away half the possibilities, so seven guesses are always enough. This is called binary search, and computers use it to find data quickly. Player 1 guesses first, so Player 2 always gets a last chance to tie.