Caro-Kann 4...Nd7


Early ...h6 moves are a well known trap in this line. You have to specifically study and analyze when that move is right and when it is wrong. Playing it at the wrong time leads to the major trap and loss of the Queen (or checkmate). NOT playing it when it is time to play it can also be costly as you have to get the White pieces away from your King.

Yes, 7...h6 is a blunder. It has been a while since I have played the Caro, and I play 3.f3 as White, but I seem to recall it is actually the very nextmove when ...h6 is supposed to be played, but there, at move 7, it is indeed a blunder. I think, if memory serves me right so don't quote me, that the Bishop on f8 is supposed to be moved first, and only then 8...h6.

The idea is h6 Ne6
This is not the idea, just a tactical justification.
The idea is to play Bc4 or Bd3 to provoke e6 (because of concrete problems on f7 or g6...) and block Bc8.
White could play other move orders, Bc4 or Bd3 first which lead to same lines (if black doesnt fall into 5...h6? 6.Ne6).
There is the Bellon variation with 4...h6 preventing Ng5 before playing Nd7, which is possible and not so bad if black really doesn't want white playing Ng5 though. Strange looking but I don't know if there is a clear refutation.

Yes, 7...h6 is a blunder. It has been a while since I have played the Caro, and I play 3.f3 as White, but I seem to recall it is actually the very nextmove when ...h6 is supposed to be played, but there, at move 7, it is indeed a blunder. I think, if memory serves me right so don't quote me, that the Bishop on f8 is supposed to be moved first, and only then 8...h6.
Indeed, the line goes like this :