How to beat your 5 year old at Guess Who?®

This works for the most recent version of the game.

Does your person have facial hair?

• Yes

  Does your person have a beard?

  • Yes

    Is your person bald?

    • Yes

      Does your person have brown hair?

      • Yes

        Your person is James

      • No

        Your person is David

    • No

      Does your person have black hair?

      • Yes

        Your person is Andy

      • No

        Does your person have white hair?

        • Yes

          Your person is Jon

        • No

          Your person is William

  • No

    Does your person have brown hair?

    • Yes

      Is your person white?

      • Yes

        Your person is Justin

      • No

        Your person is Connor

    • No

      Does your person have black hair?

      • Yes

        Your person is Tyler

      • No

        Does your person have a fat nose?

        • Yes

          Your person is Joshua

        • No

          Your person is Jake

• No

  Does your person have blue eyes?

  • Yes

    Does your person wear earrings?

    • Yes

      Does your person wear glasses?

      • Yes

        Your person is Emily

      • No

        Your person is Megan

    • No

      Is your person bald?

      • Yes

        Your person is Nick

      • No

        Does your person wear glasses?

        • Yes

          Your person is Joseph

        • No

          You person is Kyle

  • No

    Is your person wearing a hat?

    • Yes

      Does your person have brown hair?

      • Yes

        Does your person have bushy eyebrows?

        • Yes

          Your person is Daniel

        • No

          Your person is Rachael

      • No

        Does youre person have black hair?

        • Yes

          Your person is Chris

        • No

          Does your person wear earrings?

          • Yes

            Your person is Ashley

          • No

            Your person is Brandon

    • No

      Is your person bald?

      • Yes

        Does your person have bushy eyebrows?

        • Yes

          Your person is Zachary

        • No

          Your person is Alex

      • No

        Does your person have black hair?

        • Yes

          Your person is Sarah

        • No

          Your person is Matt

I used R8 implementation of c4.5 found at http://www2.cs.uregina.ca/~dbd/cs831/notes/ml/dtrees/c4.5/tutorial.html to generate the decision tree. The files I used were player.names and player.data. If you come up with a better feature set that creates a smaller decision tree, please let me know.

Getting started with creating the decision tree

wget http://www2.cs.uregina.ca/~dbd/cs831/notes/ml/dtrees/c4.5/c4.5r8.tar.gz
tar xf c4.5r8.tar.gz
cd R8/Src
make
wget http://joey.mazzarelli.com/guess-who/player.names
wget http://joey.mazzarelli.com/guess-who/player.data
./c4.5 -f player -g -m 1