kylemeister wrote on 01/31/08 at 05:01:55:
By "Carlsbad" I was thinking of 7. Rc1 a6, after which Black, if allowed, plays ...dc, ...b5 etc.,
Generally accepted nomenclature:
After the typical sequence 1 d4 d5 2 c4 e6 3 Nc3 Nf6 4 Bg5 Be7 5 e3 0-0 6 Nf3 Nbd7 7 Rc1,
7...a6 introduces the Swiss defence, so named because a group of Swiss players, notably Henneberger, analysed it in the 1920s, focusing on strengthening Black's game in the new structure that arises after the critical 8 c5 (attributed to A.Rabinovich, 1922).
8 cxd5 exd5 is the Carlsbad variation, since this exchange was played in a similar position three times in the Carlsbad 1923 event. Later the term "Carlsbad structure" began to be used to cover the QGD Exchange structure generally, not just after ...a6. (But Watson confines the use of Carlsbad to the QGD Exchange with Nf3. I'm not sure that this is a particularly useful distinction.)
The Swiss defence was extensively analysed in the 1920s and various tweaks were tried by both sides. White often tried to make all possible useful moves before playing Bd3, so as not to lose a tempo. Black experimented with inserting ...c6 and/or ...h6.
The evolution of the QGD does not seem to be very well covered in modern books, although Kasparov's DVD and certain annotated games in his My Great Predecessors series are useful, as is Watson's Mastering the Chess Openings Volume 2. An interesting older source is Chess from Morphy to Bovinnik by Imre Koenig.
When Ziatdinov was having his great run of success in US Swiss events a few years ago his main black weapon against 1 d4 was the Swiss defence (an odd choice in Swisses, you would think, but it worked for him) and so anyone interested in playing this line for Black should find his games and annotations useful.