Perpetual check
Far behind on material? Checks the king can never escape save the game as a draw.
The idea
Far behind on material? Check the king for ever and draw the game.
- The white king has walked out to c6, far from its own pieces.
- Bb7+ checks from right next to it; taking the bishop loses to a mate.
- After Kb5, Ba6+ checks again, and the king must go back to c6.
In a game: When you are lost on material, count the other king’s squares: does each one meet a check?
How the lesson begins
Hamppe against Meitner, Vienna 1872, a game known as the Immortal Draw. Black has given up the queen, a bishop and both knights, and the white king has walked all the way to c6. White is a queen and a knight up, for two pawns.
Step through a normal move such as ...Be6: White is simply winning. Black needs something better.
- 16... Be6
Find the move
The white king is far from home, with no pieces near it. Find the check that starts a run of checks it cannot escape.
A hint
The bishop on c8 has two checks. Try the one that lands next to the king.
Show the answer
16... Bb7+
Bb7+ checks from the square right next to the king, and the engine now calls the game level. A run of checks that the king can never escape is called perpetual check.