Sicilian Defense:Smith-Morra Gambit

Named after Pierre Morra of France and Ken Smith of the United States. White gives a pawn for fast development and open lines.

It is reached after 3 moves: 1. e4 c5 2. d4. It is a line of the Sicilian Defense.

Black is to move and has 23 legal moves. Over the next four moves — two for each side — the game can branch into 805,987 different games. Those games reach 269,067 different positions: most positions can be reached in more than one way, 3 on average.

The Lichess opening list names 32 further lines after this position, such as Morphy Gambit (2... cxd4 3. Nf3) and Halasz Gambit (2... cxd4 3. f4).

The same moves can be played in 2 different legal orders that all reach this position. For example 1. d4 c5 2. e4, which starts as the Queen's Pawn Game.