Sicilian Defense:Najdorf Variation, Adams Attack

Named after the American player Weaver Adams. 6. h3 prepares g4; it became fashionable at the top level in the 2010s.

It is reached after 11 moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. h3. It is a line of the Sicilian Defense.

Black is to move and has 30 legal moves. Over the next four moves — two for each side — the game can branch into 1,628,900 different games. Those games reach 537,019 different positions: most positions can be reached in more than one way, 3 on average.

No later position on this line has a name of its own in the Lichess opening list: the names end here.

The same moves can be played in 8,568 different legal orders that all reach this position. For example 1. e4 c5 2. d4 d6 3. Nf3 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. h3, which starts as the Sicilian Defense: Smith-Morra Gambit.