Author: Uri Blass
Date: 07:49:13 08/25/01
Go up one level in this thread
On August 25, 2001 at 07:22:32, Uri Blass wrote: >On August 25, 2001 at 01:38:23, Mig Greengard wrote: > >>On August 25, 2001 at 00:04:53, K. Burcham wrote: >>> >>>i cannot imagine how stefan felt watching this game. shredders score >>> quickly went up 5 points, and maintained a five point advantage for quite >>> some time. stefan had to feel very confident. somewhere about move 60 >>> stefan probably witnessed his score drop tremendously. there must have >>> been a lot of surprised chess enthusiasts in the game room. >> >>I talked about this during this game and a few others I commented live at >>KasparovChess.com. I enjoy comparing how computers play and solve problems >>compared to how a strong human would go about it. Shredder had an undeniable >>advantage for most of the game, and a clearly winning advantage after it won the >>exchange. It then started doing things that a strong human would never consider >>for purely pragmatic reasons. I mentioned at the time, while Shredder was still >>well in the plus, that it was playing with fire. (Gromit did the same thing, >>turning a simple draw into a wild ride that it lost to Junior.) >> >>Your first obligation when you have such a position is to eliminate counterplay. >>This isn't 100% possible against a strong opponent, but you certainly work to >>simplify the position in order to keep control. The last thing you want is to >>see the position sharpen so much that, despite your objective advantage, one >>error in calculation can cost you the half or full point. >> >>Which is exactly what happened to Shredder. It's eval did not swing so much >>because it evaluated the position incorrectly when it was at +5 (although it >>does tend to be overoptimistic, like many programs, which is why I have so much >>admiration for Junior's more conservative, and generally more accurate, evals), >>but because it allowed the position, despite being advantageous, to get so sharp >>that each half-ply meant life or death. This is often fatal for humans and >>computers alike. >> >>Mikhail Tal would stir up unfathomable complications on the board because he >>trusted his instincts and because he knew he could calculate better than anyone >>in the world. But even Tal knew when it was time to simplify into a winning >>endgame! No matter how well you calculate, you don't give your opponent a batch >>of passed pawns (if you can help it) if only because nobody is perfect and you >>just might have missed something. >> >>Programs are vulnerable here because they always play the "best move," and not >>the most practical move. They can't see the inherent complexity of a coming >>position, just the eval. > >If they have the right eval they can see the complexity of the position in the >evaluation and reduce the score. > >If they see that thei eval is dropping inspite of being more than +5 >they should understand that something may be wrong with their evaluation and >change their evaluation function > >Here is shredder analysis at move 60(it is on slow p200 but I gave it a lot of >time) > >You can see that Shredder eval is >5.87/7 >5.79/8 >5.69/9 >5.65/10 >5.46/11 >5.52/12 >5.34/13 >5.33/14 > >It dropped almost every iteration > >Deep Junior 7 - Shredder >[D]4r2k/7p/2q5/p2p1PP1/5N2/2b1p1PK/4B3/3Q4 b - - 0 1 > >Analysis by Shredder 5.32: > >60...d4 > -+ (-6.18) Depth: 1/2 00:00:01 >60...d4 61.Ne6 > -+ (-6.17) Depth: 2/4 00:00:01 >60...d4 61.Ne6 Qe4 > -+ (-6.00) Depth: 3/6 00:00:01 >60...d4 61.Ne6 Qe4 62.g4 > -+ (-6.11) Depth: 4/8 00:00:01 >60...d4 61.Ne6 a4 62.Kg4 > -+ (-5.86) Depth: 5/10 00:00:01 >60...d4 61.Ne6 Qd5 62.Bc4 Qxc4 63.Qxd4+ Bxd4 > -+ (-5.86) Depth: 5/10 00:00:01 >60...d4 61.Ne6 Qe4 62.Bd3 Qd5 63.Kg4 > -+ (-5.73) Depth: 6/12 00:00:02 12kN >60...Re5 61.g4 d4 62.Ba6 > -+ (-5.74) Depth: 6/12 00:00:02 20kN >60...Re5 61.Kg4 d4 62.Qc2 Qe8 63.Bc4 > -+ (-5.80) Depth: 6/12 00:00:03 31kN >60...Re5 61.Qc2 d4 62.Kg4 Kg8 63.Qb3+ Kg7 64.Bf3 > -+ (-5.68) Depth: 7/14 00:00:05 69kN >60...d4 61.Ne6 Qe4 62.Nxd4 Bxd4 > -+ (-5.69) Depth: 7/14 00:00:05 76kN >60...d4 61.Ne6 Qe4 62.Bd3 Qe5 63.Qh5 Rc8 > -+ (-5.87) Depth: 7/14 00:00:06 105kN >60...d4 61.Ne6 Qd6 62.Qd3 Rb8 63.Qc4 Qe5 64.Kg4 > -+ (-5.79) Depth: 8/16 00:00:10 196kN >60...d4 61.Qb3 Qa8 62.Kg4 a4 63.Qf7 Rf8 64.Qd7 Qe4 > -+ (-5.69) Depth: 9/18 00:00:35 944kN >60...d4 61.Qb3 Qd7 62.Kg4 a4 63.Qb5 Qxb5 64.Bxb5 Ra8 65.Bxa4 Rxa4 > -+ (-5.65) Depth: 10/20 00:01:02 1771kN >60...d4 61.Qb3 Qc7 62.Kg4 Rc8 63.g6 Rf8 64.gxh7 Qb8 65.Qe6 Kxh7 66.Kf3 > -+ (-5.46) Depth: 11/22 00:02:55 5261kN >60...d4 61.Qb3 Qd7 62.Kg4 a4 63.Qb6 Rf8 64.Qc5 Ra8 65.Qe5+ Qg7 66.Qd5 Ra5 > -+ (-5.52) Depth: 12/24 00:09:22 17679kN >60...d4 61.Qb3 Qd7 62.Kg4 a4 63.Qb6 Rf8 64.Qe6 Qg7 65.Qd5 Rc8 66.Bf3 Qe7 67.Ne6 >Kg8 > -+ (-5.34) Depth: 13/26 00:25:19 49607kN >60...d4 61.Qb3 Qd7 62.Kg4 Bb4 63.Qc4 Re5 64.Ne6 Bc5 65.Bd3 Bb6 66.Kf4 > -+ (-5.33) Depth: 14/28 02:18:32 295630kN > > > > > > Don't blame Shredder for the Rd8 blunder; that's the >>symptom, not the disease that all comps face. > >Rd8 blunder is not the only problem in the game because even without this >blunder shredder did not have the advantage when it played Rd8. > >Uri I can add that shredder5.32 is even more optimistic at move 61 and again does not expect Junior's move(only slow p200 but I believe that it is less than 10 times slower than the hardware in wccc) Deep Junior 7 - Shredder 4r2k/7p/2q5/p4PP1/3p1N1K/2b1p1P1/4B3/3Q4 b - - 0 1 Analysis by Shredder 5.32: 61...d3 62.Nxd3 -+ (-5.62) Depth: 1/2 00:00:00 61...d3 62.Nxd3 -+ (-5.44) Depth: 1/2 00:00:00 61...Kg8 -+ (-6.51) Depth: 1/2 00:00:00 61...Kg8 -+ (-6.51) Depth: 1/2 00:00:00 61...Kg8 62.Qb3+ Qc4 -+ (-6.23) Depth: 2/4 00:00:00 61...Kg8 62.Qb3+ Kh8 63.Qf7 -+ (-5.78) Depth: 2/4 00:00:00 61...a4 62.Bb5 -+ (-6.05) Depth: 2/4 00:00:00 61...a4 62.Ne6 Kg8 -+ (-6.34) Depth: 2/4 00:00:00 61...Qd7 62.Kg4 a4 63.g6 Rb8 64.gxh7 -+ (-6.38) Depth: 2/4 00:00:00 61...Qd7 62.Kg4 a4 63.g6 Rb8 64.gxh7 -+ (-6.38) Depth: 2/4 00:00:00 61...Qd7 62.Ne6 Bd2 63.Qb3 -+ (-6.09) Depth: 3/6 00:00:00 61...Qd7 62.Ne6 Kg8 63.Nxd4 Qxd4+ 64.Kh3 -+ (-6.05) Depth: 3/6 00:00:00 61...Re5 62.g4 Kg8 -+ (-6.07) Depth: 3/6 00:00:00 61...Re5 62.g4 Kg8 -+ (-6.07) Depth: 3/6 00:00:00 61...Qe4 62.Bb5 Rc8 -+ (-6.08) Depth: 3/6 00:00:00 61...Qe4 62.Bb5 Re5 -+ (-6.21) Depth: 3/6 00:00:00 61...Qe4 62.Bd3 Qe5 63.Kg4 -+ (-6.35) Depth: 4/8 00:00:00 61...Qe4 62.Kg4 Qe5 63.Bc4 Rb8 64.Qh1 -+ (-6.10) Depth: 5/10 00:00:00 61...Qe4 62.Kg4 Rf8 63.Bd3 Qe5 64.Qh1 Rf7 65.Ng6+ Kg8 66.Qxh7+ -+ (-6.10) Depth: 5/10 00:00:00 61...Qe4 62.Qd3 Qxd3 63.Bxd3 Kg7 64.f6+ Kf8 65.Bxh7 -+ (-5.98) Depth: 6/12 00:00:01 22kN 61...Rf8 62.Bf3 Qd6 63.Ne6 e2 64.Nxf8 exd1Q -+ (-5.99) Depth: 6/12 00:00:01 26kN 61...Rf8 62.g4 Qd6 63.Kg3 Rg8 64.g6 hxg6 -+ (-6.09) Depth: 6/12 00:00:01 35kN 61...Rf8 62.g4 Qd6 63.Qf1 Rc8 64.Bb5 Kg8 -+ (-5.86) Depth: 7/14 00:00:03 78kN 61...a4 62.Ne6 Kg8 63.Kg4 Qe4+ 64.Kh3 -+ (-5.87) Depth: 7/14 00:00:04 120kN 61...a4 62.Kg4 Bb2 63.Qb1 a3 64.Ne6 Qd5 -+ (-6.01) Depth: 7/14 00:00:06 178kN 61...a4 62.Kg4 Re5 63.Qb1 a3 64.g6 h6 65.Qb3 -+ (-5.93) Depth: 8/16 00:00:10 280kN 61...Rf8 62.g4 Qd6 63.Qf1 Rc8 64.Ne6 Kg8 -+ (-5.94) Depth: 8/16 00:00:11 331kN 61...Rf8 62.Kg4 Qe4 63.Bd3 Rxf5 64.Bxe4 h5+ 65.Kxf5 -+ (-5.94) Depth: 8/16 00:00:13 388kN 61...Qe4 62.Qd3 Qe5 63.Qb5 Qxb5 64.g4 Qxe2 65.Ng6+ hxg6 -+ (-5.95) Depth: 8/16 00:00:14 420kN 61...Qe4 62.Qd3 Qe5 63.Ne6 Rc8 64.Qb5 Qe4+ 65.Kh3 Kg8 -+ (-6.10) Depth: 8/16 00:00:15 458kN 61...Qe4 62.Qd3 Qe5 63.g6 Qf6+ 64.Kh3 hxg6 65.Nxg6+ Kg8 66.Qb5 Re4 -+ (-5.87) Depth: 9/18 00:00:20 603kN 61...a4 62.Kg4 Re5 63.Qb1 a3 64.g6 Qa8 65.gxh7 a2 66.Ne6 axb1Q -+ (-5.88) Depth: 9/18 00:00:25 776kN 61...a4 62.Kg4 Bb2 63.Bf3 Qc4 64.Qe2 Kg8 65.Qxc4+ Re6 66.Nxe6 -+ (-5.91) Depth: 9/18 00:00:31 969kN 61...a4 62.Kg4 a3 63.Qb3 Qd6 64.g6 Rg8 65.Kh3 Rb8 66.Qf7 -+ (-5.80) Depth: 10/20 00:01:12 2169kN 61...Qe4 62.Qd3 Qxd3 63.Bxd3 a4 64.Ne6 a3 65.Nxd4 a2 66.Bb1 -+ (-5.81) Depth: 10/20 00:01:57 2984kN 61...Qe4 62.f6 Bd2 63.Qb3 Rf8 64.Kg4 d3 65.Bxd3 -+ (-5.82) Depth: 10/20 00:03:13 4809kN 61...Qe4 62.f6 Bd2 63.Qb3 Rf8 64.Kg4 d3 65.Bxd3 Qg6 -+ (-5.57) Depth: 11/22 00:05:18 8457kN 61...Qe4 62.f6 Qc6 63.Qb3 Rf8 64.Qe6 Qc7 65.Bb5 Be1 66.Kg4 Qc5 -+ (-5.48) Depth: 11/22 00:06:04 9819kN 61...a4 62.Kg4 -+ (-5.49) Depth: 11/22 00:06:17 10218kN 61...a4 62.Kg4 a3 63.Qb3 Qd6 64.g6 hxg6 65.Nxg6+ Kg7 66.Nf4 Re5 67.Ne6+ Kg8 -+ (-5.76) Depth: 11/22 00:07:56 13202kN 61...a4 62.Kg4 Rf8 63.Qc2 a3 64.Bf3 Qd7 65.Bd5 Re8 66.Be6 Qc6 67.g6 Qa8 68.gxh7 -+ (-5.67) Depth: 12/24 00:17:22 32547kN 61...a4 62.Kg4 Rf8 63.Qc2 a3 64.Bf3 Qd7 65.Bd5 Re8 66.Be6 Qb5 67.Qe4 Rd8 -+ (-5.61) Depth: 13/26 00:54:28 109136kN Uri
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