1. e3(or e4) [...]

2. Bc4 [...]

3. Qf3 [...]

4. Qxf7++

This coded message is the conventional way of writing checkmate in four moves in the game of chess. All good chess players know how to guard against this ploy. There is likely to be a decent chess player in the TOK class who should be invited to explain the principles of standard “algebraic notation” and to demonstrate the sequence of moves live, using a real chess board.


Next, students should find a partner and get ready to play tic-tac-toe (noughts and crosses) for a solid five minutes. When the time is up, ask if anyone in the class is unbeaten? Announce that the next task is to formulate a succinct algorithm that, if implemented tirelessly, will ensure that a player never loses at tic-tac-toe.

Combine pairs in groups of four to tackle the following questions:


  • In what other ways could checkmate in four moves be described?
  • To what extent is chess a mathematical algorithm? 
  • Is it possible to create an algorithm for chess that would ensure that a player never loses (analogous the one we attempted for tic-tac-toe)?  Explain your response. 
  • No machine could beat a chess master until IBM's Deep Blue beat Garry Kasparov under standard tournament time controls in 1997. What advantages did the supercomputer have over the human brain? What did Kasparov have that the machine did not have?
  • Can a machine think? 
  • Can a machine know?

Printable Pdf of questions.

Deep Blue: a silicon-based chess master?

Deep Blue: a silicon-based chess master?