On the beach, scratching marks in the sand with a stick, my 4-year-old son was already good enough to force a draw in noughts and crosses, also known as tic-tac-toe. In case there is anyone on the ...

With perfect play, tic-tac-toe always ends in a draw. But what if you can play for both sides? Reading time 3 minutes Although most view tic-tac-toe as a kid’s game, puzzle designers see it as a ...