tarrasch french, f4 sideline

Hi. I have recently started to study the french opening from the black perspective.  Among other things, I have bought the Simon Williams download on the subject. He recommends to advance the a-pawn against white's plan of en early f4. To stop the f-pawn to advance further to f5, which is a common idea for white (getting play in the f-file), Williams recommends g6 and h5. He specifically recommends meeting g4 with h5. However, the computer doesn't like h5 after g4,  because of f4... and if black responds with hxg4 as Williams suggests in his dvd, then suddently the computer gives approx a + 5 advantage to white. So I wonder if anyone has any idea of what is the best plan after g4, h5, f4 in these types of positions?

Please post a diagram, not everybody is familiar with French Tarrasch sidelines. 

Sorry, new in this forum, didn't realize i could include a board :-)

Williams says to always meet g4 with h5, but the computer likes f5 for white very much, and hxg4 which Williams suggests works out tactically for black, is a bad move according to the computer. So what do you think black should play after f5 in this position? (or similar positions with this kind of pawn structure in the tarrasch french). 

I have a suspicion the move order is not right - doesn't 7 f4 hang a pawn? Probably you mean the line starting with 5 f4.

Yeah, you might be correct about the move order. It is the f4 line of the tarrasch yes. 

The line given by S.Williams is this one, with analysis u can find on chess.com :

I added some personal comments, for some pupils but of course, french language...

The video on chess.com about all this :

https://www.chess.com/video/player/why-simon-loves-the-french-the-rogue-a-pawn

So u forgot c5xd4 at some point. About f5 for white, I don't think it is frightening and what is your engine?

My Stockfish doesn't like it.

If we look at this position (with f5) :

After some moves, I don't see enough compensations for the piece for white, do u?

8....a5 is interesting and typically risky Williams idea. 5f4 isn't a sideline at all, and probably white's best chance of aiming for an advantage.

Most of all it should give the resident forum stats and software nuts some clue about the limits of their tools, in finding and using chess concepts. Yeah, fat chance of that...

Actually I might have made an error and played Bd7 in this variation, because then the king has nowhere to escape after gxf7. It is probably the reason why the computer disliked the move. 

But in the position above, the computer actually suggests 13... hxg4,, 14. fxe6, gxf3 15. exf7+ Kxf7 16 Rxf3+ Kg8. Other black moves, such as 15...Kd7 after exf7 gives white an edge (according to Stockfish). So quite a crazy line

 I suggest you put the software away, because as if often the case not using it very well, and what you claim can't be verified.  The only thing can see is true, is that it is quite an unbalanced position.

You might be right about that. So putting the computer aside, what move do you think is best after 13... hxg4,, 14. fxe6, gxf3 15. exf7+?

I thought the 15...Kd7 mentioned by IM Poucin looked ok, and when using software 15...Kxf7 16Rf3ch Bf5 looked better than kg8. So think black ok after f5.

To be honest am personally happier in the calmer positions after 3...c5 4pxp Qxp, or 4Nf3 pxp. Once lost a horrible game after 3...Nf6 with a similar a5 idea in positions without f4.  Don't really know your style of play but you might be happier with less ambitious 3...c5 approach too.

 Guimard's variation is quite a good response to Tarrash and is quite "intuitive" and easy to play in my opinion.

But in this Tarrash Nf6-f4 line, I like black here...

I agree Bf5 is maybe a better move, and the computer actually prefers that move after some think. It's a complex position.

I'm trying to expand my opening repertoire. I have to practice it in real games before I know how I like to play it. 

Guimard's variation, is that with the knight moving to c6 without pawn moving to c5?

IM pfren: I wasn't too concerned about the move order when i set up the board, I just wanted to reach the position.  The positon in #3 is correct. I don't worry about it, I'm just curious.