How should I have defended?

on move 15 B-d3 instead of N-c3

Originally posted by Thomaster
on move 15 B-d3 instead of N-c3

Now that would be an interesting move if achievable 😉

Qe1 on move 25?

(edit - never mind, nope.)

At move 11, Queen side was undeveloped and the King side was undefended. I would start there.

hello, maybe 12.Nd2 with the idea of Nf1
or
13.Rxd5? Maybe?
or
14.h6? maybe?

12.Bxd5 is my move.Trade light square bishop for his d5 knight giving you a target to work on (isolated d-pawn).
Or else 12.a4 trying to get some queenside play going but I'm not sure if that acomplishes anything.

Nc3 on move 11 or 12 would have been better. Since you're already up a pawn, doubled pawns aren't such an issue and you need to figure out how to negate the potential kingside attack - trading off knights helps do this. 12. Bd2 isn't very good, because it blocks the defender of d4. After Bd2, 12... Bf6 or 12... Bd6 followed by 13... Qh4 (which was played) will recover the pawn.

Supporting the Rook was a big mistake.

I agree with haml, you should concentrate more on developing your pieces before going on the attack.

I never play the Ruy Lozez because I'm a 1.d4 guy, but I can tell you that I'd rather play the variation of the Ruy that you're playing. I don't like the bishop/knight exchange where I end up with doubled pawns.

Mate in 1?
22 ... Qg2-h1+
23 Ke2-g1 Qxg1#

I'd say pawn structure, you let black run the center and thus you were cut apart like butter.

Originally posted by AThousandYoung
Game 1121861

Don't play 15.Nc3

after 19.Re2 the game should have gone like

19... Qh3+ 20.Kg1(or Ke1) Qh1+ 21.Kf2 Qg2+ 22.Ke1 Qg1#

Originally posted by tamuzi
Mate in 1?
22 ... Qg2-h1+
23 Ke2-g1 Qxg1#

I'd say pawn structure, you let black run the center and thus you were cut apart like butter.

Kf2 stops that.

Playing 14.g3 with your light squared bishop on the other side of the board left many weak spots for him to attack. But 14.h3 doesn't work either after 14...Bxh3. So the mistake was made beforehand, in allowing 12...Bd6 followed by 12...Qh5.

I have tried a pawn grabbing line that looked very similar to this game in an otb match, and ended up getting brutally attacked as well, so maybe 8.Nxd5 requires more accurate play than both of us suspected...

Originally posted by UserChevy
Playing 14.g3 with your light squared bishop on the other side of the board left many weak spots for him to attack. But 14.h3 doesn't work either after 14...Bxh3. So the mistake was made beforehand, in allowing 12...Bd6 followed by 12...Qh5.

I have tried a pawn grabbing line that looked very similar to this game in an otb match, and ended up getting br ...[text shortened]... ally attacked as well, so maybe 8.Nxd5 requires more accurate play than both of us suspected...

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

but black should have played 14... Qxd4

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

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.