What is wrong with 1.d4 c5? It seems to be rarely played and I was curious if it is refuted or why it is considered bad. Is it worthwhile to play at the club level? Also, what is the name of this opening?

Thanks

Sandman wrote on 11/23/09 at 13:15:55:


This move is a bit better than its reputation, but White should be able to keep a slight advantage after 1.d4 c5 2.d5 e5 (Benoni Wall) 3.Nc3 d6 4.e4 followed by Bb5 or f4 (depending on what Black plays), or 1.d4 c5 2.d5 g6 3.e4 d6 4.Nc3 (Schmid Benoni) Nf6 5.Nf3 Bg7 6.Bb5. It's not a bad surprise weapon, since because of its rarity most players don't have a well-prepared response to 1...c5.

Dean wrote on 11/23/09 at 22:17:55:


Well, ECO and NCO think that 5. Bb5+ or 5. f4 should lead to an edge.

jitb wrote on 11/24/09 at 11:53:07:


This is similar to the dubious 'Clarendon Court Defence' with 1.d4 c5 2.d5 f5?!.

I can't remember the exact refutation, but it goes along the lines of (in the quoted line) 4.g3 Nf6 5.Bg2 g6 6.Nc3 Bg7 7.Nh3 0-0 8.Nf4 Na6 9.0-0 Nc7 and now I recall White plays either a timely Rb1 to prepare b4 or Qc2 to prepare e4. Unfortunately I can't remember which plan, but it can be found in SOS 3.

In the 2...f5 move order, 3.Nc3 Nf6 4.f3 is also possible although 4...e6 with the idea of 5.de6 d5! isn't too bad for Black.

4. e4 is the killer move against the clarendon court alright.

But we're deviating : 1.d4, c5 normally leads to the openings Stefan Bücker wrote a book about (Hawk, Vulture, and Woozle in english iirc)

kylemeister wrote on 11/25/09 at 17:33:52:


Overall, I agree. After 4.e4 Black can play 4...fe4 5.f3 (5.Nc3 Nf6 makes less sense now that g4 is not possible) 5...Nf6 6.Nc3 Nbd7 (Black can probably get away with 6...ef3, but without a board in front of me I'll recommend a safer option) 7.fe4 Bg7 8.Nf3 0-0 and after ...Ng4-e5, there is no reason why Black should be worse. (If 9.h3 Nh5 exploiting the weakness of the dark squares in White's camp).

I'm very surprised that in SOS 4, Ehlvest doesn't consider ECO's advocated 5.Nge2 - I think +/- is a slight exaggeration since ...Qb6 in ECO's line looks dubious, but White's position is much more comfortable and Black is under serious pressure.

Gambit wrote on 11/30/09 at 02:20:34:


After 3.b4, in the worst case scenario Black can play 3...e6 4.a3 Nf6 5.Nd4 d5 when Black is certainly equal and perhaps even a little bit better after a future ...e5.

Gambit wrote on 11/30/09 at 08:30:26:


I assume you mean 5.Nd4 d5 and then 6.e3 Bd6 7.Bd3 0-0 etc.

I would dispute this variation and suggest 7...e5 8.Nf5 Bc7 as an improvement, but I don't have time to analyse this right now. On the other hand, 7.c4 instead of 7.Bd3 may be better in order to liquidate Black's centre since now 7...e5 8.Nb5 is somewhat annoying for Black.