Winning & Losing Positions

Work backwards from the end

An interactive lesson with 5 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• W positions have a move to an L position. L positions only lead to W positions.
• Work backwards from the end to classify positions.
• Winning means always moving to an L position.

Steps

1. Two kinds of position
2. Take one or two
3. Who should go first?
4. Twenty-one
5. The general rule