Paul Keres, along with Soviet rival Mikhail Botvinnik, Vasily Smyslov, Max Euwe and Samuel Reshevsky contested the title in a tournament split between The Hague in the Netherlands and Moscow.

That is why these masterpieces should be studied. In the World Championship game of Mikhail Botvinnik vs Mikhail Tal, which appears below, black’s amazing 21st move has been discussed ever since ...