Old Indian Defense

It is reached after 3 moves: 1. d4 d6 2. c4.

Black is to move and has 27 legal moves. Over the next four moves — two for each side — the game can branch into 680,769 different games. Those games reach 223,054 different positions: most positions can be reached in more than one way, 3.1 on average.

The Lichess opening list names 3 further lines after this position, such as Rat Defense, English Rat (2... e5).

The same moves can be played in 2 different legal orders that all reach this position. For example 1. c4 d6 2. d4, which starts as the English Opening.