Author: Miguel A. Ballicora
Date: 13:39:07 10/16/01
Go up one level in this thread
On October 16, 2001 at 16:02:42, Uri Blass wrote: >On October 16, 2001 at 14:24:00, Robert Hyatt wrote: > >>On October 16, 2001 at 11:13:38, John Merlino wrote: >> >>>On October 16, 2001 at 07:58:15, Steffen Jakob wrote: >>> >>>>Hi, >>>> >>>>this is a position from a blitz game Hossa - Sjeng: >>>> >>>>[D]7k/4QP2/7p/6rP/8/1K6/6r1/8 b >>>> >>>>For a human it's obvious that this is a draw. Hossa was rather clueless and >>>>thought that white was winning. Are there any engines which show a draw value at >>>>once (without significant search depth)? >>>> >>>>Greetings, >>>>Steffen. >>> >>>Chessmaster 8000 sees the draw in less than a second: >>> >>>Time Depth Score Positions Moves >>>0:00 1/3 1.18 7319 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 >>>0:00 2/4 0.95 23824 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 >>>0:00 3/5 0.00 45109 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 R1g2+ 13. Ke3 >>>0:01 4/6 0.00 110883 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 R1g2+ 13. Ke3 >>>0:02 5/7 0.00 246089 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 R1g2+ 13. Ke3 >>>0:04 6/8 0.00 498686 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 R1g2+ 13. Ke3 >>>0:08 7/9 0.00 1039196 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 R1g2+ 13. Ke3 >>>0:16 8/10 0.00 2092486 1...R2g3+ 2. Kc2 Rg2+ 3. Kd3 R2g3+ >>> 4. Kc4 R3g4+ 5. Kc3 Rg3+ 6. Kb2 >>> Rg2+ 7. Kc1 Rg1+ 8. Kd2 R1g2+ 9. >>> Ke3 R2g3+ 10. Ke2 Rg2+ 11. Kf1 >>> Rg1+ 12. Kf2 R1g2+ 13. Ke3 >>> >>>jm >> >> >>It isn't seeing "the draw". It is seeing "a draw". > > > >I do not know >The score is positive at depth 2/4 when the main line is 22 plies >so it can see advantage for white and only later changes it's opinion to draw >score. > > "the draw" is way deep >>here. "the draw" is probably beyond 40 plies deep. > >It is possible that it can see 40 plies at depth 3/5 or bigger depthes >45109 positions may be enough if you search the right lines. There is 24 distinctive positions where the white king can go. After the move 25 the rook can check and find that as repetition. So, that is 50 plies. However, with check extensions it is just 25 plies. With some other extensions this can be reduced considerably. Besides, hashtables can be tricking here the program to see the draw earlier since 25 plies is true with a certain move ordering. Otherwise, the hashtable will start to be filled up with draw scores earlier (which in this case helps but it could be wrong). IMHO, I think that it is possible that CM is seeing "the" draw. Regards, Miguel > >I do not know. > >Uri
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