I haave Black and play against JeanMiche who opened with 1 b4 !?

I decided to answer not classically with 1... d5 (classical answer is 1... e5 followed by 2... Bxb4) but after transposition , we landed in the classical line...

Is this a promising game ?

One plus of d4 is often the pawn structure is similar for white with e3 d4 c4 with an e4 push and/or queenside expansion.

I think the only way to tell how much opening theory you need is to play plenty of games. If you hit a period when you're getting bad or dull positions from the opening, then it becomes obvious you need to learn something more.

For d4 there may not be a lot of different first move options but black still has unique defenses they can pretty much "force". When I played d4 I had to play against
1Orthodox
2KID
3Nimzo
4Slav
5Dutch
6Semi Slav
7QGA
8Benko
9Benoni
10Albin
11Budapest
12Chigorin
13Old Indian
14Tarrasch

<whatthefat> and I did some (very simple) number crunching re the openings, which is gathered at Lasker vs Capablanca, 1936 and also at my forum page. <Whatthefat> had the idea of determining results in games of 40 moves or less compared with games of more than 40 moves. We anticipated that Black would score better in longer games (since it's much easier to lose quickly with Black than with White, and if Black lasts 40+ moves there is a good chance he has equalized). Generally, we were right, but there were some interesting wrinkles. Here were our main conclusions:

Of all defenses surveyed, the Sicilian provided the best results.

The Nimzoindian gave the best results against 1. d4. Unfortunately, White can avoid that. The Queen's Indian didn't score badly for a 1. d4 defense, but you'd never confuse its results with the Sicilian's.

1. d4 games of all sorts were generally more likely to draw in under 40 moves than 1. e4 games.

Even in games over 40 moves, White retained an advantage in almost every opening. But the extent of the advantage varied enormously, from 3% in the Sicilian to well over 20% in the Tarrasch (among others). White was much likelier to retain a big advantage in results in games over 40 moves that had started 1. d4 than in games that had started 1. e4. (White retained an enduring pull in Ruy Lopez games, though.)

against (1...e5):

1. b4 e5
2. Bb2 Bxb4
3. f4!? ...

Even after 4. ... Qh4+ White seems to have an advantage, although an ugly one:

Well, good luck. See you again in 20 years.
Do you wanna know a secret before you start to analyze it? It can't be refuted.

a) gain an initiative on the queenside by means of placing the QN on a6, where it can come to the irritating spot b4 and controls c5

b) get an attack on White's uncastled king by pushing his f- and g-pawns and massing forces on kingside

while White's main principles are control of the center, quick development and king safety (if this last one sounds weird, don't ask me, I was more concerned with the Black side).

With a couple test games, we came to the conclusion that Black is better (3...a5! thus deserving, in my opinion, an exclamation mark). Two games is quite a small sample of course and improvements for White can surely be found. In game 1 I was White and, not understanding White's strategy properly, got totally blown off the board:

click for larger view

In the second game I was in the more familiar Black territory and, while not getting a huge advantage, played an OK game against a superior opponent.

click for larger view

I don't recommend you play 1.b4 if you wan't a Najdorf reversed. I suggest you 1.a3, possible variations;

1.a3 Nf6 2.c4 d5 3.cxd5 Nxd5 4.d3 e5 5.Nf3 Nc6 6.e3

1.a3 e5 2.c4 Nf6 3.d3 d5 4.cxd5 Nxd5 5.Nf3 Nc6 6.e3

1.a3 d5 2.e3 e5 3.c4 Nf6 4.cxd5 Nxd5 5.d3 Nc6 6.Nf3

This "Double Polish" game continued 4.e3 c6 5.Nf3 a5 6.bxa5 Qxa5 Notice that Black refrained from playing ...Bb7, but instead opted for the outflanking ...c6,...a5. White can possibly improve by tossing in c4 at some point.

<<Ferdinand Schmidt>: <Die verkannte Schacheröffnung : neue Wege nach Saragossa 1. c2-c3.> Mädler, Dresden 1999, ISBN 3-925691-20-0>