One of my online chess games. Some annotations below . . .
4. Nxe5?! I never saw this before in a Four Knights Game but it actually has a name: the Halloween Gambit. In exchange for a knight, White gets to chase black knights around the board with pawns.
9. …c6? This is not such a good move if White had played 10 h4 because the knight at g6 doesn’t have many options. Instead, 9 …cxd6 10 exd6 Qf6 11. Qe2+ Qe6 12. Nb5 Qxe2+ simplifies with a material advantage.
11. Nxb5? Just backing the bishop up to d6 looks better.
14. …a5? White could have played 15 Bd2 attacking the pawn.
15. O-O?
15. …Nh6? This gives White time to play 16. Be3 (which he doesn’t) and cut off the diagonal to his king so Black can’t play 16. …Qb6+, which I should have played this move.
16. f5?? I’m going to give that two question marks because I think it’s pretty much over now.
16. Qd5? 16. …Bxh6 gives Black one less piece to attack with.
22. f6? I don’t know if it makes sense to hand out question marks in a completely lost game but 22. Rae1 is an obvious move here.
24. fxg7? There aren’t any good moves left. This leads to a forced mate.
25. hxg4 Or 25. Kg3 Qf2+ 26. Kxg4 Be2+ 27. Qxe2 h5+ 28. Kg5 Qf6#.
You are right, 9. .. c6 is not a good move, nor the answer 10. Bc4 ( bad place because of b7-b5 and because no combination with Qf3 possible). Brause used to play here 10.g3 . GM Milov played 10.Bd3. But 10.h4 is also good.
But there is more ! 9.d6 also is not the best because in the classical Nc6 line the gambit is refuted by 9.d6 cxd6 10.exd6 Qf6 11.Nb5 Nxf4 ! To avoid this White can play 11.Qe2 (with enough compensation ). Nevertheless the most promising move here is 9.Qe2 !
If interested I can give you the analyses of both 11.Qe2 and 9.Qe2
Paul Keiser: Now that you’ve pointed it out, I can see the merits of the Qe2 moves.