Author: Paulo Soares
Date: 03:03:52 03/04/00
Go up one level in this thread
On March 04, 2000 at 00:58:38, Len Eisner wrote: >On March 04, 2000 at 00:46:38, Len Eisner wrote: > >>On March 03, 2000 at 20:25:37, Paulo Soares wrote: >> >>>On March 03, 2000 at 15:44:14, José Antônio Fabiano Mendes wrote: >>> >>>>On March 02, 2000 at 23:28:15, Paulo Soares wrote: >>>> >>>>>On March 02, 2000 at 18:30:52, Len Eisner wrote: >>>>> >>>>>>On March 02, 2000 at 14:16:04, Paulo Soares wrote: >>>>>> >>>>>>>On March 01, 2000 at 22:35:33, Len Eisner wrote: >>>>>>> >>>>>>>>[D]6bk/8/7P/p7/1p1R4/r2B1PP1/6K1/8 b - - 0 45 >>>>>>>> >>>>>>>>Junior 6 played Rxd3! against Hiarcs 7.32 in a 5/3 blitz game on my PIII 500. >>>>>>>>It’s a nice exchange sac that wins by force by queening one of the passed pawns. >>>>>>>> >>>>>>>>Len >>>>>>> >>>>>>>I didn't get to find a winner line for black. Below a possible >>>>>>>variant(the best?): >>>>>>> >>>>>>>1... Rxd3 2. Rxd3 b3 3. h7 Bc4 4. Rd4 a4 5. Rxc4 >>>>>>>a3 6. Rb4 a2 7. Rxb3 a1=Q 8. Re3 Kxh7 9. Kf2 >>>>>>> >>>>>>>Paulo Soares, from Brazil >>>>>> >>>>>>In the game Junior 6 played Kxh7 instead of Bc4 in your line. Here’s how it >>>>>>went from the position in the diagram: >>>>>> >>>>>>1...Rxd3 2. Rxd3 b3 3. h7 Kxh7 4. Rd7+ Kh6 5. Ra7 Bh7 6. Ra6+ Kg7 7. Rb6 Bc2 8. >>>>>>Rb7+ Kf6 9. Rb6+ Ke7 10. Rb7+ Kd6 11. Kf2 a4 12. Ke3 a3 13. Kd2 a2 14. Ra7 b2 >>>>>>15. Rxa2 b1Q 16. Rxc2 Qg1 17. Rc3 Qxg3 and black wins. >>>>>> >>>>>>I guess it’s possible for white to save the game, but I don’t see how. >>>>>> >>>>>>Len >>>>> >>>>>I believe that, following the line of the game, 6. Rxa5 are better than 6. Ra6+. >>>>>All the analyses were made with the help of a program. >>>>> >>>>>1... Rxd3 2. Rxd3 b3 3. h7 Kxh7 4. Rd7+ Kh6 5. Ra7 Bh7 6. Rxa5 >>>>>Bd3 (6... b2 7. Rb5=) 7. Ra3 b2 8. Rb3 b1=Q 9. Rxb1 Bxb1= >>>>> >>>>>Paulo Soares >>>> >>>>Instead of 5...Bh7,Black should play 5...Bc4.Now White can neither >>>>take the a-pawn[6.Rxa5 b2] nor check the Black king.Most likely >>>>Black has a win here. JAFM >>> >>>I believe that, same having other interesting variants, >>>white draw after 5... Bc4 6. Rb7. >>> >>>1... Rxd3 2. Rxd3 b3 3. h7 Kxh7 4. Rd7+ Kh6 5. Ra7 Bc4 6. Rb7 a4 7. >>>Rb4 a3 8. Rxc4 a2 9. Ra4 b2 10. Rxa2 b1=Q 11. Re2 >>> >>>The position now is similar to the final position of the first variant >>>that I placed (message 99888) and I don't know as black can win. >>> >>>Paulo Soares. >> >>Good analysis by both of you. For continuity, here’s a diagram of the final >>position in the above line. >> >>[D]8/8/7k/8/8/5PP1/4R1K1/1q6 b - - 0 54 >> >>I agree this position is drawn. As an experiment, I removed the white pawns one >>at a time to get into the 5-piece tablebase. Interestingly, if you remove the f >>pawn the position is drawn, but if you remove the g pawn, it’s mate in 60! >> >>Anyway, I think black may have some winning chances by playing 8…b2 instead of >>8…a2 as in the above line. By pushing the b pawn, I think black makes it harder >>for white to sac the rook in a way that draws. >> >>I’m currently analyzing the position after b2 with Junior 6. >> >>Len > >Oops. I meant to say that by pusing the b pawn it makes it harder for white to >capture one of the black pawns in a way that draws. > >Len Some analyses. I placed two crictical positions, both after white's move number 15. I don't know if tablebases helps in these positions, because I have my tablebases on CD. The idea is not to allow the blacks' king to enter in the column "e" to help black's Queen. 1... Rxd3 2. Rxd3 b3 3. h7 Kxh7 4. Rd7+ Kh6 5. Ra7 Bc4 6. Rb7 a4 7. Rb4 a3 8. Rxc4 b2 9. Rb4 Kg6 10. Rb5 Kf6 11. Rb6+ Ke5 12. Rb8 Kd4 13. Rb3 Kc4 (13... a2 14. Rxb2 a1=Q 15. Re2!? Qd1 16. Re4+ Kd3 17. Re5 Qd2+ 18. Kh3 Qc1 19. f4) 14. Rxa3 b1=Q 15. Re3!? Qc2+ (15... Qd1 16. f4 Kd4 17. Re5 Qc2+ 18. Kf3) 16. Kg1 Kd4 17. Re4+ Kd3 18. Re1 Qc3 19. Re4 Kd2 20. Kg2 First Critical position: [D]8/8/8/8/3k4/5PP1/4R1K1/q7 b - - 0 15 Second critical position: [D]8/8/8/8/2k5/4RPP1/6K1/1q6 b - - 0 15
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