Breaking every opening principle-And getting away with it!

What a disaster! My opponent breaks all the opening principles we are taught at the beginning levels but ends up positionally crushing me! I've never felt like such a patzer in a long time. I have notes on what I think are bad moves, but I want to know what I could have done better and what I should learn from this game.

I don't have a board avail, but 7 Ne5 looks like fun for white.

It seems you were a bit overeager to capture.  As you mentioned, your opponent didn't develop for many moves, but 8. Bxg8 exchanges your developed bishop for an undeveloped knight.

11. O-O isn't really castling into an attack - it's just castling into an open position.  The f-file is semi-open, and your h-pawn is en prise.  Black even declines to take the h-pawn until it captures the g-pawn and threatens black's bishop.

The opposite color bishops don't necessarily increase drawing chances unless they're the only pieces left.  At the time, there was still clearly more than enough material to force a decisive game.

At the finale, you move the king back into the empty kingside - I'd even speculate that it's not really the case that black had a strong attack.  The white kingside is still weakened from the opening.

I suppose I'd look at some of the principles you mention in context.  Sure, castling is often a good thing, but not if it doesn't improve your king's safety.  After 8...Rxg8, black is unable to castle kingside, but in this game, the kingside didn't offer much shelter for either side.

thats why his rating is 1638

Thanks Random, you're right about trading. When someone plays an opening like this I tend to overextend while trying to refute his play. I really need to fix that..

Castling was possibly your biggest mistake, your King was safer where it was and your Rook was more dangerous on the H file.  At a glance instead of castling hxg5 seemed better to me.  If he recaptures with the Bishop then Nxg5 forces him to recapture again and you either win a pawn or get your Queen into the heart of his King-side, reinforced by your Rook (that's gotta equal trouble!).  If he captured with the Rook then he loses it, and if he captures with the pawn then he opens your Rook right up down the H-file.

Another error by castling in this position is that you allowed him to develop his Queen onto a dangerous diagonal WITH check (effectively a free move).  Although I agree that black made some fundamental opening errors in this game, you didn't exploit them!  Remember, if your opponent doesn't do the normal thing then it sometimes means that the normal thing is not what you do either, as doing other things can better take advantage of his abnormal position.

Let us not always blame the principles.

[First, there was an interesting offensive line 6.Pxg5 fxg5 7.g3 ?! fxg3 8.Nxg5 with a strong kingside attack. I did not analyze it all the way, but looks promising.]

Bxg8 and O-O have already been discussed by RandomPrecision, so I won't repeat. Pushing pawns from in front of the king while the heavy pieces are not yet exchanged is also not a good idea unless playing against a very weak opponent - you do it only if you are sure of tangible gain, exchange of queens, or of castling safely to the other side.

From my experience (maybe even more from my GO tournaments experience): It is extremely dangerous to convince yourself that opponents move is bad unless you know exactly how to punish it. If you dont you just become more unpatient and annoyed: "my opponent plays bad moves all the time so i should win soon" or "my opponent plays bad moves so why position is still quite equal". Both those sentences went through my mind many times during tournament games and I assure you that unless you can get rid of them as soon as they appear your ability to play normal game is impaired. That leads to mistakes and eventually lost games.

Maybe that played its part in this game too?

Opposite coloured bishops are better for the player who has the attack, because you can't defend what he is attacking. As someone mentioned above - they're only useful for drawing when it comes to the endgame, and then, only in certain positions with accurate play.

Your premature castling kingside let him set up a kingside attack, using his pawns as battery rams. His pawns seized the center, while yours were to passive and limited the movement of your pieces. You shouldn't have traded your developed pieces for his undeveloped pieces while you were trying to apply pressure.

A first idea that comes to my mind is 7.hxg5 fxg5 8.Ne5 threatening both Nf7 with a fork and Qh5+ with a deadly attack. I'm not sure how black can meet this.

- just noticed it has already been pointed out by Tonydal - sorry : I reacted before reading other posts