How to defend vs knight attacking castled king's pawns?

there's hardly anything to say. h6 is definitely the way to go in the diagram, and you played well and were completely winning (until the blunder), so i really must be completely missing the point.

the one suggestion i would make is 29..Qxd5, which pretty much closes the deal. he's forced to trade queens or give up h4 after which there is less than nothing

You´re right that would have fastened things up. Shame on me for not seeing it .

@Hellball

You ask how to deal with those patterns.
My impression is that you simply lack experience in certain positions, and your tactical skills can probably be much improved over time.

The Ng5 move was not very dangerous, and an experienced player would "see through that".
Make sure you don't "see ghosts". Stick to the facts, and train yourself to improve your chess calculation and intuition.

On the other hand, in that position :
Black has chosen for a very closed pawn structure, with very little play.
There's basically no open files, which makes all (yes, all) black pieces passive or almost passive.

I'd say that the black queen is kind of active, but the bishop is a bad bishop, and the 2 rooks are passive, while the black knight is not really happy on e7 and neither on f5.

Even when the black knight came to f5 you can see that it is a "lone wolf". There's no cooperation and proper coordination between that knight and the other black pieces.

You must find a balance between attack and defense.
Learning when to move which pieces to the attack and when not (because sometimes players play too many pieces back for the defense, while lacking manouvre space, and therefore getting into trouble against stronger players who know how to exploit that)

I would like to advise you to check the game of GM Ulf Andersson. He's been a very good defender. I believe that players like Karpov almost never won with the black pieces against Ulf.

You also must work on your tactics.
Tactics are good, in attack and defense, and also in an endgame (rook endgames, pawn endgames, all can involve tactics).
A 1400 tactics rating here of yours leaves quite some room for improvement.
You did quite some puzzles here, but it is good to do a few puzzles every day. Do that for at least 3 or 4 months.
Get into that discipline to improve your chess daily.
Now I do 5 puzzles every day during breakfast (one from chessvideo.tv, one daily puzzle from chess.com, and 3 from chesstempo. Before I did 4 of them since > 1 year).

Good luck, enjoy your chess !

very good advice. i would add that your problem isn't dealing with the "knight raid", but rather how to handle threats to your king in general, so i will resume my thoughts in three points:

1 - get experience
2 - review your games
3 - the french might not be the opening for you (this isn't a conclusive statement, just something to think about)

Lightsss is right thats the best advise that could be given here.

Well, achja said enough about your and you opponents tactical skills, let me add some strategical facts:

In this structure d4 is the critical square:

if you play 5...c4?, his d4 pawn can not be exchanged any more by your c-pawn. But if d4 safely protects e5, f4-f5 becomes stronger because f-pawn does not need to protect d4 any more. So c5-c4? makes f4-f5 much stronger.

With your pawn on c5 you can answer f4-f5 with c5xd4 and then e5 is not protected any more. So he has to prepare this better. You can use this extra time for your purposes.

But he played it bad of course. So that you managed to get a winning position.

But then later you again missed the importance of d4. If you play 29...Qxd4!, his far advanced white pawns on king side will immediately turn into a weakness. and therefore his King will become a weakness too. Look at his King after 29...Qxd4!

This is meant with: 'answer an attack on one wing with a breakthrough in the center': the far advanced pawns on the wing will become a weakness when the center is open.

Also, you handled the good bishop/bad bishop problem not very well:

In this structure Bc8 and Bf1 are the bad bishops and Bf8 and Bc1 are the good bishops. Try to avoid to exchange your good bishop against his bad bishop (so dont play 9...Be7) and try to exchange your bad bishop against his good bishop (so play 4...Bd7!)

Wrong by me: Bf8/Bf1 are the good bishops and Bc8/Bc1 are the bad bishops. Sorry.

I've looked through the comments and didn't see anyone speaking about move 17. Why did you not just take the knight? What were you afraid of? Queen and rook lining up? But white has to spend several tempi to do that. Don't forget about his back rank issue as well. And even if you didn't have Qe1# in that variation you could easily defend against Rh3 & Qh5 with a rook move and Ng6.

So as it turns out you were not consistent with your h6 move, you could as well do something else.

That knight move would be much stronger if there were bishops on the board especially when aimed at your king.

#18, yeah, I knew that was the play after 17. Rc3, so I thought that might be an intentional sac and couldn't see an easy way to block an attack by queen and rook down the h-file without losing out on my own attack on the queenside. In retrospect, there wasn't much of an attack there at all.

I guess the way to solve that problem is brute force calculation (which is my biggest weakness -- when I calculate I play good moves, but I rarely do that - hence my highly inconsistent level of play).

You should have played hxg5 imo. NEVER fear a sh*tty attack. That's how you will lose. A free knight is a free knight remember that. The attacking player feeds on fear and will thrive. Always accept a bad sac. If you fail to defend, learn to defend, but don't be afraid to take a yummy free piece, when opponent doesn't have compensation. Just my opinion though.