The Monkey's Bum (Nigel Povah vs Shimon Kagan, 1977)

In the 1970s, there was a certain wave of popularity for the Modern Defence. Grandmasters such as Raymond Keene and Jonathan Speelman (and later Yasser Seirawan) used to play it on a regular basis. 2

In the search for refutation, British International Master Nigel Povah started investigating a rapid assault on the f7 square. He devised a weird variation involving a sacrifice of the d4 pawn in return for the rapid development.

When he showed the variation to his friend Ken Coates, the latter declared: “If that works then I’m a monkey’s bum!” The name stuck ever since.

1. e4 g6
2. Bc4 Bg7
3. Qf3 e6
4. d4 Bd4
5. Ne2 Bg7
6. Nbc3

Povah was defeated by black in this 1977 game, but the opening has allowed the much more popular and respected Monkey's Bum Deferred to evolve against the Modern Defense.