St. George Defense

Tony Miles famously answered world champion Anatoly Karpov’s 1. e4 with 1...a6 in 1980 — and won.

It is reached after 2 moves: 1. e4 a6.

White is to move and has 30 legal moves. Over the next four moves — two for each side — the game can branch into 370,351 different games. Those games reach 132,811 different positions: most positions can be reached in more than one way, 2.8 on average.

The Lichess opening list names 3 further lines after this position, such as Zilbermints Gambit (2. d4 e5) and Polish Variation (2. d4 b5 3. Nf3 Bb7 4. Bd3 e6).