9.Bxf6 gxf6 10.Nd5 f5: main line is variation 1 of 6 in the Sicilian Sveshnikov course, a advanced opening course for Black (ECO B33). It runs 32 moves and begins 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 …. White pins the knight and then breaks up Black's pawns with Bxf6. Black takes with the g-pawn and hits back at once with ...f5. Then Black trades the light-squared bishop for the d5 knight and gains space with ...e4. 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 and opens lines for the queen and the f1 bishop.
1... c5 – The Sicilian. Black fights for d4 from the side and keeps the game unbalanced.
2. Nf3 – White develops and prepares to open the centre.
2... Nc6 – Black develops and watches the d4 and e5 squares.
3. d4 – White opens the centre.
3... cxd4 – Black trades a wing pawn for a centre pawn and gets the half-open c-file.
4. Nxd4 – White takes back with the knight.
4... Nf6 – Black develops and attacks the e4 pawn.
5. Nc3 – White defends e4 with the knight.
5... e5 – The Sveshnikov. Black kicks the d4 knight and takes space in the centre. The price is a hole on d5.
6. Ndb5 – The main line. The knight eyes d6, the square that the e5 push left weak.
6... d6 – Black covers d6 at once. Now no white knight can land there.
7. Bg5 – White pins the f6 knight. The bishop fights for the d5 square.
7... a6 – Black kicks the b5 knight away. It has to go to the edge of the board.
8. Na3 – The knight goes to a3. It is offside, but it can come back through c4 or c2.
8... b5 – Black takes the c4 square from the knight. The pawn may also push on and kick the c3 knight.
The lesson goes on for 16 more moves, each with its explanation.
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