And don't forget that Seirawan was known as a good theoretician, too.. 

STEFANOS wrote on 07/25/11 at 17:00:47:


The question is how booked-up Seirawan was and if Mamedyarov chose to play it against Seirawan because he wasn't sure either?

STEFANOS wrote on 10/27/10 at 16:34:18:

Concerning the above topic , the line I mentioned was choosen by Seirawan to defeat Mamedyarov.
[Event "World Chess Team Championship"]
[Site "Ningbo CHN"]
[Date "2011.07.24"]
[EventDate "2011.07.17"]
[Round "7"]
[Result "1-0"]
[White "Y Seirawan"]
[Black "S Mamedyarov"]
[ECO "A43"]
[WhiteElo "2635"]
[BlackElo "2765"]
[PlyCount "58"]

1. d4 c5 2. d5 f5 3. e4 fxe4 4. Nc3 Nf6 5. g4 h6 6. h3 d6 7. Nge2 e5 8. Ng3
Be7 9. Bg2 Na6 10. Ncxe4 Bd7 11. O-O Nxe4 12. Bxe4 O-O 13. f4 exf4 14. Bxf4
Bg5 15. Qd2 c4 16. Bxg5 Qxg5 17. Qxg5 hxg5 18. Bf5 Bxf5 19. Nxf5 Nb4 20.
Ne3 Rxf1+ 21. Rxf1 c3 22. bxc3 Nxa2 23. c4 a5 24. Nf5 a4 25. Nxd6 a3 26.
Nxb7 Nb4 27. c3 Nd3 28. c5 Nf4 29. d6 1-0
Chessbase mentioned as grave error the move23... a5, and computer suggests Nc3 with equality. I like also 23...g6 to keep away the Knight from f5. In the next move the Azeri played the awful 24...a4 and lost , but either Rd8 or Nb4 offer more in this position. Possibly the Claredon Court is not unsound, but very difficult against a prepared GM. For club level is fine.

My personal feeling it is  by playing ala Staunton Gambit in the Dutch Defence creates lots of problems to black. 1.d4 c5,2.d5 f5,3.e4 fxe4,4.Nc3 Nf6, and now 5.g4 . Also I remembered Rowson in NIC to say his own experience with this variation and said it was unsound. Another bad thing it is the big hole on e6 after a posssible d6 to support c5, which gives nice chances for a fork by a knight.

Interesting. 

I've faced it against a 2000+ and against a 2200+. I won against the expert, lost against the master. I had never seen it before I faced the 2000 player and just winged it.  Against the master, I played a critical line and got the better game but lost in the complications. The master has played it against 2400+ opposition. 

My own impression is that the Clarendon Court is far enough from "normal" chess that the better player will win.  It's a good way to level the playing field against a booked up player (me).  But it's probably not quite solid enough for professional or correspondence chess. I certainly wouldn't want to try to make a living defending such an opening.

Sources which may be of interest in this context:
Levitt: Foxy Openings, A complete defence to 1.d4 (GM-Video 1995)
Okhotnik/Appleberry: New Chaos Counter Attack, ChessMix.com
Ehlvest: The Dutch Benoni, in SOS 4 (2006)
Maurits Wind: Clarendon Court, in Kaissiber #25 (2006; 3 pp.). Based on the sources above, with many new ideas. The line which led to a decline of 2...f5's popularity is (also) discussed. 
(Full disclosure: That's my magazine!)
Avrukh, 1.d4 vol. 2 (2010)
Bücker: ChessCafe.com. Checks Avrukh's recommendation and comes to the conclusion: about =. 
(Another full disclosure: my column. But it's free, so any potential damage will only be virtual.)

Valiantangel wrote on 06/21/10 at 09:40:10:


I bought the foxy tape mentioned and used it in speed games with good results.  I'm not so sure of it's soundness either but in the g3 line here maybe Black could play ...Na6, ...Nc7 and put the Bishop on d7 to support the ...b5 break.