@cathexis

Some openings are extra-tactical from their very first tabiya, like the Traxler variation or the Botvinnik Semi-Slav. Some openings start as relatively positional and mostly stay that way, like the exchange Slav, though you can certainly attack on the wing using the semi-static center.

To some extent it's typical of every opening to become more tactical as the game progresses, since (1) as the pieces are developed and come into contact, more tactics become possible, and (2) as the game progresses, the board gets more open, so there are more squares for the pieces to move to and more to calculate.

The deceptive positional-looking beginning and subsequent explosive transformations in the French, however, go beyond that. These things do happen in  other openings, of course, like the King's Indian, but are particularly common in certain French lines. Here's a typical illustration (this game is not theory after move 10).
 
1. e4 e6 2. d4 d5 3. Nd2 Nf6 4. e5 Nfd7 5. c3 c5 6. f4 Nc6 7. Ndf3 Qb6 8. h4. It looks at first like a strategically clear game. White has built and defended a huge center--for example, the d-pawn is attacked three times and defended three times.  White now decides to take advantage of his central control by launching a wing attack. He sees that Black, lacking central space, can neither get many defending pieces to the kingside quickly nor easily castle queenside. 8...cxd4 9. cxd4 Bb4+! 10. Kf2 (The first hint of trouble. White has to move his king because 10. Bd2 Nxd4 11. Nxd4 Qxd4 just loses the d-pawn). 10... f6 Black, instead of defending, tries to reduce White's center. Will it be enough? 11. Bd3? White doesn't think so. He is not impressed and develops another attacking piece. He intends to play Rh1-h3, hide his king on h2, bring his other pieces over toward the kingside, and gradually overwhelm Black. He should at least, however, have gotten his king off the f-file first. 11...Nxd4!? Black sacrifices a knight to destroy the White center! (Actually, he misses an even better version, the winning 11... fxe5 12. fxe5 Ndxe5! 13.Nxe5 Qxd4+ 14. Be3 Qxb2+ 15. Ne2 Qxe5, which wins his knight back while keeping three pawns). 12. Nxd4 fxe5 13. fxe5 Nxe5 14. Bc2 14...Ng6 threatens to win the pinned Nd4 with ...e5. 15. Bxg6+ hxg6. Now just look--our apparently strategic game has turned into an open, unbalanced shootout where Black has two mobile central passed pawns for the knight but his kingside is wrecked, while neither king will be particularly safe.

I would like to ask you Rene,

How much of what you just said is typical of most middlegame play and how much specific to the French variations you mentioned? By saying, "explode" I get the impression (perhaps correctly or not?) that you're implying some openings often begin sort of quiescent, then become aggressive later. Or perhaps, at first positional, then more sharply tactical. Whether I'm right or not, I'm hoping you might elaborate on this and perhaps list some openings or variations that often have these qualities - if that is your point? Sounds very interesting.

As Always - Thanks!

Cathexis

FreeRepublic wrote on 05/28/21 at 11:41:52:

While I respect 1...c6 at least as much as every other first move my attitude towards it is the same as towards the Sicilian: chess for blood. My results are mixed but the drawing rate is low.

Some good points being raised. It is difficult to make the decision on a repertoire to follow but is that the problem ? The goal I suggest is to achieve positions that you feel comfortable with, that make you want to work at them after a game and that you can develop a feel for. The chosen repertoire doesn't have to be a lifetime-lasting decision but there needs to be enough commitment to it to make it worthwhile. For me, it's always made sense to use a repertoire book or Chessable repertoire, as a starting point. These guys are usually considerably stronger than us, so why not use their advice ? Individual lines can be changed, maybe when you purchase a new repertoire book based on the same opening. Updates happen by your own experience and also by obtaining new information.
Developing within an opening system is always a good idea I believe, to take advantage of previous knowledge and experience e.g. of sidelines that don't change when you switch to a new main line in the same opening. Finding the line to stick with depends on many factors e.g. how strong you are, how experienced, how much time you have or want to spend on preparation and ultimately, personal taste.
For me, 1.e4 e5 needs to be played seriously as black for a period, as I believe it benefits your game. Then experimentation can lead to where you feel at home, for me the Caro Kann.
It took me a long time to decide how to answer 1.d4, as I wanted a basically universal system, ruling out the Nimzo. I've come to 1.d4 d5 but with a solid base (QGD) and an adventurous alternative (Noteboom).

FreeRepublic wrote on 05/26/21 at 21:10:37:


I really liked that book when it came out, and for a while I was referring to it a lot, but eventually one thing really bothered me. 

Normally, I don't mind books where the author isn't super-strong, and in fact for this kind of thing, an FM author is fine since that title was the limit of my ambition.

The thing is, though, in the books he says that he was a 20-something 2300-rated FM when he started seriously working on his repertoire with a Russian trainer and all. When he wrote the book, he was... a 30-something 2300-rated FM. So, does putting in a lot of repertoire work result in tangible improvement at that level? Apparently not.

an ordinary chessplayer wrote on 02/24/21 at 15:39:39:


Perhaps:
How To Build Your Chess Opening Repertoire, by Steve Giddins
http://gambitbooks.com/books/How_to_Build_Your_Chess_Opening_Repertoire.html

Konstriktor wrote on 05/25/21 at 09:16:20:


At least two others have it (although one is a Nimzo book):

https://www.newinchess.com/play-1-d4-d5-2-c4-e6
https://www.newinchess.com/the-modernized-nimzo