How should I have defended?

It looks to me like it started with your 12th move, B-d2. Kn-d2 would have allowed kn-f3 or f1 but it could have started earlier. You followed the Spanish ok for quite a few moves but its getting into the middle game that you started allowing black to develop, especially when you got your rook up in the center too early. Winning that pawn should show you how it ends up activating the opponents pieces. That rook was a sitting duck out there undefended in the center, so he got a nice tempo out of it. But then everything but the kitchen sink was aimed at your king. Most of your pieces were undeveloped on the other side of the board. Do you remember your thinking when you put your bishop out at move 12 instead of knight?

Originally posted by UserChevy
Yes, Nc3 really does nothing. But I still think allowing Bd3 and Qh5 led to kingside weaknesses that might cause trouble down the road, although the position does see defendable after Qe2 or Qf3.

Yeah, I am fully aware of the dangers of making weaknesses in front of the king.

Originally posted by tomtom232
g3 was alright after Qh3 15.Nc3 lost it... better would be 15.Qe2 or Qf3

but black should have played 14... Qxd4

Yeah, I agree. 14... Qh3 loses the momentum of the attack. After 14... Qxd4 the position is very sharp, I'd say unclear without spending a lot of time on it.

I think White made 3 critical errors in the game. 7... d5 looks bad to me and I believe that White has an objectively won game after 10... c6. I can find one other game that reached this position and White won a long, drawn out endgame after 11. Qe1. 11. d4 looks better to me. White's d-pawn should be enough to force a winning endgame.

12. Bd2? gives Black play again, restricting White's Queen and cutting off support of d4. I think I like 12. Bxd5, taking Black's well-placed Knight off the board and busting up his pawns. 12... cd 13. Nc3 Be6 (now if 13... Bd6? 14. Rxd5) and either 14. Re1 or 14. Qd3 look good to me.

12... Bd6 looks dangerous, but I believe White can fight off the attack. Black also had 12... Bf6, regaining the d-pawn with a decent game (13. Re1 [13. Re4 Bf5] Bxd4).

13. Re1?! looks too passive, allowing Black a very active game. White has a couple of interesting tries to keep the initiative:

13. Bg5 Qc7 (13... f6 14. Rxd5 looks very good for White) 14. Re1 Bxf2+ 15. Kh1 and Black's Queen is misplaced to continue attacking from c7, and I still prefer White's pawn structure.

13. Rh5!? also looks very interesting. The Rook looks misplaced but seems to stifle Black's attack and is annoying to dislodge. For example 13... g6 14. Rh6 Re8 (threatening... Bf8) 15. g3 or 13... Nf6 14. Rh4 and again the Rook refuses to be chased from the h-file (14... Nd5? 15. Qh5 looks very dangerous for Black).

But 15. Nc3? is the killer. Again, as tomtom said, 15. Qe2 or Qf3 should hold, although I like 15. Bxd5 first a little better, removing the Knight from the attack (15... cxd5 16. Qe2 or Qf3).

Thanks, that was an interesting game! 🙂

12.Bd2 is a bad move.
A typical idea for white against the Marshal gambit is to transfer the queen to the kingside to defend the light squares, and to further defend f3 via Nd2.

12.c3 Bd6
13.Re1 Qh4
14.g3 Qh3
15.Be3 Bg4
16.Qd3 Rae8
17.Nd2 Re6
18.a4

Now white has some flexibility. He has access to move the queen or knight to f1. He can open a front on the a file. And he has access for the light bishop to move to d1 if need be. The light bishop on b3 can also pin the knight temporarily if black plays f5.

Originally posted by Mctayto
Now that would be an interesting move if achievable 😉

sorry, I meant B-e3

Originally posted by AThousandYoung
Game 1121861

10. Qh5 would give black something to think about. After 10....Nf6.
11. Qxe5.. I would think Black is on the defensive rather than the other way around.

Originally posted by Buzz Meeks
10. Qh5 would give black something to think about. After 10....Nf6.
11. Qxe5.. I would think Black is on the defensive rather than the other way around.

except black doesn't play 10..Nf6 black plays 10...Nc4.

Originally posted by sonhouse
It looks to me like it started with your 12th move, B-d2. Kn-d2 would have allowed kn-f3 or f1 but it could have started earlier. You followed the Spanish ok for quite a few moves but its getting into the middle game that you started allowing black to develop, especially when you got your rook up in the center too early. Winning that pawn should show you ho ...[text shortened]... board. Do you remember your thinking when you put your bishop out at move 12 instead of knight?

I think it was a developing move intended to support Nc3, to avoid the doubled Pawns, and free the Q-side Rook.