Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. d4/4...exd4/5. O-O/5...Nxe4/6. Nc3/6...dxc3/7. Bxf7/7...Kxf7/8. Qd5/8...Ke8/9. Re1

= Nakhmanson Gambit, Ke8 Defence =

9. Re1
If Black could make five consecutive moves here, they would be:


 * ...Be7, to block the e-file and allow the king to remain on e8;
 * ...d6, to let the c8-bishop out;
 * ...Rf8 to control f5,
 * ...Bf5 to chase a rook off e4 and keep control of g6, and
 * ...h6 to keep White's minor pieces out of g5.

White's counter-plan involves putting enough pressure on e7, by doubling rooks on the e-file and placing a bishop on g5, that the Black king is forced  to shelter on f8 and block in its own rook. White can then transfer the pressure to the f-file, and the resulting stranglehold over Black's forces  should be enough to force perpetual check even if she doesn't manage to win  the piece back.

Black's plan begins with 9...Be7. It could also begin with 9...d6, but the f8-bishop isn't going to go anywhere other than e7,  whereas the d-pawn has ambitions of getting to d5 in one move if White goes  Qxe4 for some reason.

There is an alternative defensive setup with 9...Qf6. Black is hoping for 10.Rxe4+? Be7 11.Bg5 Qf7, when White must start moving pieces backwards and the Black king can hide on d8. Unfortunately, an alert White player will switch course with 10.Qxe4+! (now that the Black queen isn't on d8, ...d5 isn't going to gain a tempo on the White queen) 10...Be7 11.Bg5 Qf7 12.Ne5. However Black chooses to trade knights (12...Nxe5 or 12...Qe6 13.Nxc6) the e7-bishop  is falling, after which Black will need a miracle to win the double-rook,  opposite-coloured-bishops ending even with an extra pawn.