4.Bxc6 dxc6 5.Nxe5: the queen fork is variation 5 of 6 in the Berlin Defence course, a advanced opening course for Black (ECO C65). It runs 24 moves and begins 1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. Bxc6 dxc6 …. White trades on c6 at once and grabs the e5 pawn. Black answers with a queen fork, wins the pawn back with check and trades queens. In the endgame Black has the two bishops and stands a little better. In the lesson every move is explained on a board and then drilled; it is free.
Move by move
1. e4 – White takes the centre.
1... e5 – Black claims an equal share.
2. Nf3 – White develops and attacks e5.
2... Nc6 – Black defends e5.
3. Bb5 – The bishop attacks the defender of e5.
3... Nf6 – The Berlin. Black attacks e4.
4. Bxc6 – White gives up the bishop at once and doubles Black's pawns.
4... dxc6 – Black takes back toward the centre. The queen and the c8 bishop get open lines.
5. Nxe5 – A common inaccuracy. White grabs the pawn, but now the e4 pawn is loose.
5... Qd4 – The queen forks the e5 knight and the e4 pawn.
6. Nf3 – The best retreat. The knight goes back to protect the kingside.
6... Qxe4+ – Black takes the pawn back with check.
7. Qe2 – White blocks the check and offers to trade queens.
7... Qxe2+ – Black trades queens. The endgame is pleasant for Black with the two bishops.
8. Kxe2 – White takes back with the king. It cannot castle any more.
8... Bg4 – Black develops and pins the f3 knight against the king.
The lesson goes on for 8 more moves, each with its explanation.
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