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Subject: Re: where are the difficult test positions ? please no positions that we

Author: Vincent Lejeune

Date: 13:17:21 11/09/05

Go up one level in this thread


On November 08, 2005 at 23:31:09, Uri Blass wrote:

>On November 08, 2005 at 15:13:22, Dann Corbit wrote:
>
>>On November 08, 2005 at 14:11:12, Vincent Lejeune wrote:
>>
>>>
>>>I made 2 mistakes :
>>>Here is the key for this one :
>>>
>>>8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - c0 "Hardest";
>>>Bh3!
>>>
>>>Topalov,V (2740) - Shirov,A (2710) [D85]
>>>Linares 15th Linares (10), 04.03.1998
>>>Ftacnik :
>>> 47...Bh3!! Fascinating idea of Shirov, since black has to push his two pawns
>>>a4,d5 as quickly as possible. The bishop would obstruct the way of the king on
>>>the natural square e4, on h3 it wins a precious tempo. [ 47...a3 48.Kf2 a2
>>>49.Ke3 Bg4 50.g3 Kf5 51.Bd4÷;
>>> 47...Be4 Shirov -+ 48.Kf2 Kf5 49.g3÷] 48.gxh3 [ 48.Kf2 Kf5 49.Kf3 Bxg2+ 50.Kxg2
>>>Ke4 51.Bxf6 d4 52.Be7 Kd3 53.Kf2 Kc2 54.Bb4 d3-+] 48...Kf5 49.Kf2 Ke4 50.Bxf6 [
>>>50.Ke2 a3 51.Kd2 d4 52.Ba1 f5-+] 50...d4 51.Be7 [ 51.Ke2? a3-+] 51...Kd3! 52.Bc5
>>>Kc4 53.Be7 [ 53.Bxd4 Kxd4 54.Ke2 Kc3 55.Kd1 Kb2-+] 53...Kb3 [ 53...Kb3 54.Bc5 d3
>>>55.Ke3 Kc2 56.Bb4 a3-+]  0-1
>>>
>>>and for this one :
>>>1r3rk1/3b1p1p/pp1p1p1Q/n1q1p3/2P1P3/P1PB1N2/6PP/1R3RK1 w - - bm Nd4;
>>>Only Nd4 is possible because king is in check.
>>>
>>>Thanks for testing , Dann !
>>>
>>>On November 08, 2005 at 13:31:38, Dann Corbit wrote:
>>>
>>>>b2r3r/4Rp1p/p2q1np1/1p1P4/kP1Q4/P4PPB/2P4P/1K6 w - - bm Ra7;
>>>>r3r1k1/1p3pp1/p1bp1b1B/2q1n3/2PN4/1P5P/2BR1QP1/5RK1 w - - bm b4;
>>>>4RQ2/5p2/2q2kp1/3p4/3P2PP/8/1K6/8 b - - c0 "Draw";
>>>>8/3P3k/n2K3p/2p3n1/1b4N1/2p1p1P1/8/3B4 w - - bm Nf6+;
>>>>rnb2rk1/pp2bppp/2p5/q7/4NN2/4B1QP/PPP3P1/2KR3R w - - bm Rd5;
>>>>r3k2r/4b2p/p1n3pN/1p1q1p2/5B2/3p1P2/PP4PP/2RQR2K w kq - bm Rxc6;
>>>>1r3rk1/3b1p1p/pp1p1p1Q/n1q1p3/2P1P3/P1PB1N2/6PP/1R3RK1 w - - bm Nd4 Nh4;
>>>>1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - id Brzozka - Bronstein;
>>>>bm b8b3;
>>>>8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - c0 "Hardest";
>>>>r1b2r1k/4qp1p/p2ppb1Q/4nP2/1p1NP3/2N5/PPP4P/2KR1BR1 w - - id "Kholmov -
>>>>Bronstein"; bm d4c6;
>>>>rqb1rnk1/4n1pp/2p5/2PpPpPP/1p3N2/1P1BP3/1BQ5/1K4RR w - - id "Bischoff -
>>>>Nogueiras"; bm e5e6;
>>>>r2q1rk1/pp2bpp1/4p2p/2pPB2P/2P3n1/3Q2N1/PP3PP1/2KR3R w - - id "Karpov -
>>>>Huebner"; bm e5g7;
>>>>r2q1rk1/3nbpp1/4p2p/p1p1P3/1p1P3P/3B1b1R/PPQB1PP1/R3K3 w Q - id "Portisch -
>>>>Johannessen"; bm d2h6;
>>>>...
>>
>>
>>This one seems to be the same idea as WAC.230 (sac a rook to get a passed pawn,
>>else the wall is impenetrable:
>>[D]1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - id Brzozka - Bronstein;
>>bm b8b3;
>>
>>Since many programs can solve WAC.230 now, I am surprised that none of them can
>>see the solution to this problem.  Are you sure that the rook is compensated?
>
>I suggest that in order to check this problem you analyze the position after
>Rxb3
>
>Note that after some analysis with chess programs I do not see a forced win in
>the main line but of course it is no proof because I may miss something and
>8...Rb4 may not be the best move
>
>Rxb3 is not a mistake and black has at least a draw by that move like WAC230 but
>the question is if black has more than it.
>
>
>[Event "?"]
>[Site "?"]
>[Date "????.??.??"]
>[Round "?"]
>[White "New game"]
>[Black "?"]
>[Result "*"]
>[SetUp "1"]
>[FEN "1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1"]
>[PlyCount "18"]
>
>1... Rxb3+ 2. Kxb3 (2. axb3 a2 3. Bxa2 Rxa2 4. Rd2 (4. b4 Ra3+) 4... Ra1) 2...
>Rb6+ 3. Kc2 Rb2+ 4. Kc1 Re2 5. Rd1 Rxe3 6. Rg1 Rc3+ 7. Kd2 (7. Bc2 Rxc4) 7...
>Rxc4 8. Bc2 (8. Re1 Rb4 9. Kc1 d5 10. Re3 d4 11. Rxa3 c4) 8... Rb4 9. Rb1 Rxb1
>10. Bxb1 *

8...d5
In fact, it's not easy, I've a slight advantage for black all along with fruit
2.2.1

[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "New game"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1"]
[PlyCount "47"]

1... Rxb3+ 2. Kxb3 Rb6+ 3. Kc2 Rb2+ 4. Kc1 Re2 5. Rd1 Rxe3 6. Rg1 Rc3+ 7. Kd2
Rxc4 8. Bc2 d5 9. Rb1 d4 10. Bd1 e3+ 11. Ke2 Kd6 12. Rb6+ Kc7 13. Rb1 (13. Rb3)
13... Kc6 14. Kf3 Rc3 15. Rb3 Rc1 16. Be2 c4 17. Rxa3 Rh1 18. Kg2 Rc1 19. Kf3
Kb7 20. Ra4 d3 21. Rb4+ (21. Kxe3 dxe2 22. Kxe2 Kb6 23. a3 Rc3 24. Kf2 Kb5 25.
Ra8) 21... Kc6 22. Bxd3 cxd3 23. Kxe3 Rg1 24. Kxd3 Rxg3+ *




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