Borg Defense

Grob spelled backwards: the mirror image of the Grob Opening. 1...g5 weakens Black’s kingside a great deal.

It is reached after 2 moves: 1. e4 g5.

White is to move and has 30 legal moves. Over the next four moves — two for each side — the game can branch into 426,723 different games. Those games reach 148,124 different positions: most positions can be reached in more than one way, 2.9 on average.

The Lichess opening list names 3 further lines after this position, such as Borg Gambit (2. d4 Bg7) and Zilbermints Gambit (2. d4 e5).