Author: Terry McCracken
Date: 11:46:46 04/22/05
Go up one level in this thread
On April 22, 2005 at 14:36:40, chandler yergin wrote: >On April 22, 2005 at 12:32:15, Terry McCracken wrote: > >>On April 22, 2005 at 12:16:52, chandler yergin wrote: >> >>>On April 22, 2005 at 12:01:09, Mihaly Szalai wrote: >>> >>>>On April 22, 2005 at 09:29:13, Andrey Popov wrote: >>>> >>>>>This is the last position of the last game of Kasparov-Karpov match. >>>>>If Karpov (Black) reaches a draw, he wins the match. >>>>>Of course, White has a huge advantage. >>>>>However, I do not see any way to win. >>>>>5n1k/5Q2/4p1p1/2q1P2p/7P/6P1/5PK1/3B4 b - - 0 64 >>>>>[D]5n1k/5Q2/4p1p1/2q1P2p/7P/6P1/5PK1/3B4 b - - 0 64 >>>>>Why did Karpov resigned? >>>>>Can anybody see a series of White's moves leading to win after Qc5-b4? >>>>>Engines quickly go to score about +3.00 and stick on it forever. >>>> >>>>According to Kasparov this is the winning line: >>>> >>>>64... Qb4 65. Bf3 Qc5 66. Be4 Qb4 67. f3 Qd2+ 68. Kh3 Qh6 (68... Qb4 69. Bxg6 >>>>Nxg6 70. Qxg6 Qxh4+ 71. Kg2) 69. f4 Qg7 70. Qxg7+ Kxg7 71. Bc6+- >>>> >>>>and we can agree with him: >>>> >>>>71... Kf7 72. Kg2 Ke7 73. Kf3 Nh7 (73... Kd8 74. Ke4 Kc7 75. Be8 Kd8 76. Ba4 Kc7 >>>>77. Kd4) 74. Ke4 Nf8 75. Kd4 Kd8 (75... Nh7 76. Kc5 Nf8 77. Bb5 Nh7 78. Kc6 Nf8 >>>>79. Bd3) 76. Kc5 Kc7 77. Be4 etc. >>> >>> >>>Neither of you took the line to Mate! >>> >>>The +- & etc.. is not convincing! >>> >>>What engine can 'demonstrate' a Mate? >>> >>>The PV evals are static positional values, and meaningless unless a Mate >>>is found. >> >>What you wrote is meaningless....Chan think before you type. >> >>First you don't know whether a computer was even employed, and even if it was, >>it's not important to show checkmate, which is some distance away. > >This was posted by Uri: >"I could probe clearly higher score than +3 by yace after Qc5-b4" > >[Event "?"] >[Site "?"] >[Date "????.??.??"] >[Round "?"] >[White "New game"] >[Black "?"] >[Result "*"] >[SetUp "1"] >[FEN "5n1k/5Q2/4p1p1/2q1P2p/7P/6P1/5PK1/3B4 b - - 0 1"] >[PlyCount "16"] > >1... Qb4 2. Bc2 Qc5 3. Kh3 Qxc2 (3... Qb4 4. f4) 4. Qxf8+ Kh7 5. Qf7+ Kh8 (5... >Kh6 6. Qxe6 Qxf2 (6... Qb1 7. Kh2 Kg7 8. Qf6+) 7. Qf6 Qxf6 8. exf6) 6. Qxe6 >Qxf2 (6... Qe4 7. Qf6+) 7. Qf6+ Qxf6 8. exf6 Kg8 9. g4 * > >A computer was used to evaluate the FEN position. >My comment: >"The PV evals are static >positional values, and meaningless unless a Mate is found." > >If the engine cannot find a Mate; what good is the eval? >Showing a Plus or a +- is misleading, if a win is beyond the capability of the >analysis module. You need more moves to take it a proper ending. > >There are many positions where a +- is shown, or even as much as a +(2.00) >and the position is still a Draw. You must see the flaw in your logic? Of course there is a margin of error, but Chan, a machine need not see mate to see it is clearly winning. I don't need to see mate 30 moves down the road to know whether I'm winning, nor do you. If the position is won, you can rely that a computer will usually see the win, but mate may be too distant. The same can be said about us. > > >> >> >>And if it were all computer, to state and I quote, "The PV evals are static >>positional values, and meaningless unless a Mate is found." Isn't correct >>regardless. > >This is true: >The PV evals are static positional values, unless a forcing line is found >and that will be reflected in the PV, usually going to Mate.
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