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

= Nakhmanson Gambit =

8. Qd5+
White has played the Nakhmanson Gambit, a hair-raising sacrifice of a whole knight  for an assault on the wandering Black king.

Good news for Black players: the Nakhmanson Gambit simply doesn't work. There is a way to emerge from the complications into a peaceful position with at least an extra pawn.

Bad news for Black players: the Nakhmanson Gambit is a nasty surprise if you haven't seen it before, thanks to this position. The natural plan of retreating the king to e8, followed by putting the bishop on e7 to shield the king from checks, is what White wants. It allows White to escape with a draw even if Black finds the best defensive moves.

Black's route to advantage instead begins with the ridiculous 8...Kf6! This just happens to work, though a player searching for some principle behind it might note that the king is  temporarily immune from checks on f6, until the e4-knight is captured. This means Black gets a crucial tempo to put a defensive piece on e7 without it immediately getting pinned along the e-file.