Guess Who? Strategy: Which Question to Ask First and Why Rare Traits Are a Trap

The only thing that matters is the split

A question in Guess Who? is a bet on both answers at once. If eleven of the remaining faces have brown hair and thirteen do not, the answer removes eleven or thirteen — either way you are close to halving the board. If only three faces wear a hat, a 'yes' is a near win but a 'no' removes three cards and you have spent a turn. Over a whole game the even splits win far more often than the long shots.

Turn one

Count the traits on the full board before the first question. Hair colour and eye colour tend to split it most evenly; glasses, hats and beards are the rare ones. Open with the most even split you can find, then re-count what is left and repeat.

The last few faces

With four faces left you need two questions if they split two-and-two, which they usually can. With three left, one question that isolates a single face wins next turn either way. With two left, ask — never guess. A wrong guess ends the round and the extra question costs you nothing if the opponent is also down to two.

Reading the computer

The computer's questions are information. If it asks about glasses and then about blond hair, you know its remaining candidates are all one way on both traits, and you can estimate how many faces it has left. When it is down to two, it will guess next turn, so if you are also close, take the guess a turn early rather than a turn late.