Puzzle of the week #343

Submitted by Eugen on Sun, 04/08/2018 - 23:28
Four Knights
Chess Diagram
[Event "Puzzle #343"][Date "2018.04.08"][Result "0-1"]1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Nd4 5. Ba4 Bc5 6. Nxe5 O-O 7. Nd3 Bb6 8. Nf4 d5 9. Nfxd5 Nxd5 10. Nxd5 Qh4 11. O-O Bg4 12. Qe1
34 years ago this was opening theory white had to avoid. It can still be used today against opponents who do not know it. Your tasks:
a) What is the name of the opening?
b) What had white done wrong?
c) Black to move and win

Total available points for this puzzle is 15. The answers will be published next time together with puzzle #344.

Puzzle #342 solution:
Gameknot opening sample, 2007. This week's best answers are by the top players:
a) Black has lost a pawn, left his King in the center and also left the diagonal h5-e8 unprotected
b) White has developed the King side pieces and castled. It should attack and take advantage of black's mistakes before he can fix them
[Event "Puzzle #342"][Date "2018.03.31"][Result "1-0"]1. e4 e5 2. Nf3 Nf6 3. Bc4 h6 4. Nxe5 d5 5. exd5 Nxd5 6. Qf3 Be6 7. O-O f6 {diagram} 8. Qh5 Ke7 (8... Bf7 9. Qxf7#) 9. Ng6 Kd6 10. Nxh8 {white is up a Rook}

Correct solutions:
Coby, Lyvia, Matthew - 15 points
Joey, Eric, Blake - 14 points
Aiden, Zhengyu - 11 points
Glyn, Walter, Mengbai, Lucas - 9 points
Jacey, Steven - 5 points
Chris - 2 points