Queen's Gambit Declined:Albin Countergambit, Lasker Trap

Named after Emanuel Lasker: after 6. Bxb4? exf2+ 7. Ke2 Black wins with an underpromotion, 7...fxg1=N+.

It is reached after 10 moves: 1. d4 d5 2. c4 e5 3. dxe5 d4 4. e3 Bb4+ 5. Bd2 dxe3. It is a line of the Queen's Gambit Declined.

White is to move and has 30 legal moves. Over the next four moves — two for each side — the game can branch into 1,649,651 different games. Those games reach 580,470 different positions: most positions can be reached in more than one way, 2.8 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 82 different legal orders that all reach this position. For example 1. c4 d5 2. d4 e5 3. dxe5 d4 4. e3 Bb4+ 5. Bd2 dxe3, which starts as the English Opening.