Author: Uri Blass
Date: 12:16:59 04/12/05
Go up one level in this thread
On April 12, 2005 at 11:54:35, John Merlino wrote: >On April 12, 2005 at 05:15:43, chandler yergin wrote: > >>On April 12, 2005 at 00:23:30, John Merlino wrote: >> >>>On April 11, 2005 at 23:36:27, chandler yergin wrote: >>> >>>>On April 11, 2005 at 13:00:10, Rob Basham wrote: >>>> >>>>>On April 11, 2005 at 12:24:18, John Merlino wrote: >>> >>>>>>>New game, >>>>>>>[D]2r1r2k/4R1pp/pb6/1p6/2nqN1QB/P5PP/1PB4K/5R2 w - - 0 1 >>>>>>> >>>>>>>Analysis by Shredder 8: > ><Some Analysis Snipped> > >>>>>>>1.Bf6 Qxf6 2.Nxf6 Bg1+ 3.Kxg1 Rg8 4.Nxg8 Nxb2 5.Qxg7# >>>>>>> +- (#152) Depth: 12/42 00:00:22 7641kN >>>>>>>1.Bf6 Rxe7 2.Bxd4 Rd8 3.Qh4 Ree8 4.Nc3 Re2+ 5.Nxe2 h6 6.Kh1 Rxd4 7.Rf8# >>>>>>> +- (#152) Depth: 13/18 00:00:23 7840kN >>>>>>>1.Bf6 Rxe7 2.Bxd4 Rd8 3.Qh4 Bxd4 4.Qxe7 Rg8 5.Rf8 Bg1+ 6.Kxg1 Nd6 7.Qxd6 b4 >>>>>>>8.Rxg8+ Kxg8 9.Qd8+ Kf7 >>>>>>> +- (#150) Depth: 14/40 00:00:43 15586kN >>>>>>>1.Bf6 Rxe7 2.Bxd4 Rd8 3.Qh4 Bxd4 4.Qxe7 Rg8 5.Rf8 Bc5 6.Nxc5 Nd6 7.Qxd6 b4 >>>>>>>8.Rxg8+ Kxg8 9.Qe6+ Kf8 10.Nd7# >>>>>>> +- (#150) Depth: 15/36 00:00:43 15751kN >>>>>>>1.Bf6 Rxe7 2.Bxd4 Rd8 3.Qh4 h5 4.Qxe7 Ne5 5.Qxe5 Bxd4 6.Qxh5+ Kg8 7.Bb3+ Rd5 >>>>>>>8.Bxd5# >>>>>>> +- (#150) Depth: 16/38 00:00:47 17089kN >>>>>>>1.Bf6 Rxe7 2.Bxd4 Rce8 3.Qf5 Kg8 4.Ng5 g6 5.Qd5+ Re6 6.Rf8+ Kxf8 7.Qf3+ Ke7 >>>>>>>8.Qb7+ Bc7 9.Qxc7+ Kf8 10.Qg7# >>>>>>> +- (#150) Depth: 17/36 00:00:49 17858kN >>>>>>> >>>>>>>(, 11.04.2005) >>>>>> >>>>>>Shredder's output is incredibly bizarre here. The position is a Mate in 9, but >>>>>>not a single PV shows mate in 9 moves (although there are mates shown in 10, 7 >>>>>>and even 5 moves!??). >>>>>> >>>>>>Conclusion: Shredder found the best move, but did NOT conclusively find the mate >>>>>>in 9. >>>> >>>>THe Mate in 9 is not forced; Shredder gave all the variations leading to >>>>Mate after the Key Move. >>>> >>>>With "Best PLay" by Black it's Mate in 9. >>>> >>>>If Black errs.. he gets Mated sooner. >>> >>>I understand that, but Shredder's output still makes no sense at all. What do >>>you mean by "Shredder gave all the variations leading to Mate after the Key >>>Move"? >> A Program evaluates every possible move at each ply depth; >>that is one complete iteration. >>Shredder found a Mate at ply 12, another at ply 13, another at ply 14, >>another at ply 15, another at play 16 etc. >> >>What don't you understand? > >Simple -- take this PV from Shredder (which is the first one listed above): > >1.Bf6 Qxf6 2.Nxf6 Bg1+ 3.Kxg1 Rg8 4.Nxg8 Nxb2 5.Qxg7# > +- (#152) Depth: 12/42 00:00:22 7641kN > >A program should not announce a Mate for the side to move that is simply not >possible with best play. If I were to stop analysis at this point and post my >findings here, it would be soundly refuted by the simple fact that there is no >Mate in 5 for White. > >It seems bizarre to me that, at depth 12, the Shredder thinks that there is a >forced mate in 5 (only 9 plies away). > >jm Here is shredder9's analysis It has a better pv and does not show mate in 5 in it's pv. New game, 2r1r2k/4R1pp/pb6/1p6/2nqN1QB/P5PP/1PB4K/5R2 w - - 0 1 Analysis by Shredder 9 UCI: 1.Rxe8+ +- (3.71) Depth: 1/2 00:00:00 1.Rxe8+ Rxe8 +- (3.71) Depth: 1/2 00:00:00 1.Nf6 +- (4.07) Depth: 1/6 00:00:00 1.Nf6 Qxg4 2.Nxg4 Rxe7 3.Bxe7 Nxb2 +- (4.28) Depth: 1/8 00:00:00 1.Qe6 +- (4.30) Depth: 1/8 00:00:00 1.Qe6 +- (4.30) Depth: 1/8 00:00:00 1.Qe6 Rf8 +- (4.36) Depth: 2/8 00:00:00 1.Qd7 +- (4.38) Depth: 2/8 00:00:00 1.Qd7 Qxd7 +- (4.66) Depth: 2/8 00:00:00 1.Qd7 Qxd7 +- (4.41) Depth: 3/8 00:00:00 1.Qd7 Qxd7 +- (2.73) Depth: 3/10 00:00:00 1.Qd7 Qxd7 2.Rxd7 Ne3 +- (2.73) Depth: 3/10 00:00:00 1.Rxe8+ +- (2.74) Depth: 3/11 00:00:00 1.Rxe8+ +- (3.09) Depth: 3/11 00:00:00 1.Rxe8+ Rxe8 2.Qh5 Qd7 3.Nf6 +- (4.67) Depth: 3/12 00:00:00 1.Bf6 +- (4.68) Depth: 3/15 00:00:00 1.Bf6 +- (5.03) Depth: 3/15 00:00:00 1.Bf6 Rxe7 2.Bxd4 +- (9.96) Depth: 3/15 00:00:00 1.Bf6 Rxe7 2.Bxd4 Rce8 +- (10.02) Depth: 4/15 00:00:00 1.Bf6 Rxe7 +- (9.77) Depth: 5/15 00:00:01 1.Bf6 Rxe7 2.Bxd4 Rce8 3.Bc3 Be3 +- (9.69) Depth: 5/15 00:00:01 1.Bf6 Rxe7 +- (9.44) Depth: 6/19 00:00:01 25kN 1.Bf6 Rxe7 2.Bxd4 Rce8 3.Bxb6 Nxb6 4.b3 Nd5 +- (9.43) Depth: 6/19 00:00:01 29kN 1.Qf5 +- (9.44) Depth: 6/20 00:00:01 71kN 1.Qf5 +- (9.79) Depth: 6/24 00:00:01 82kN 1.Qf5 Qe5 2.Rxe5 Nxe5 3.Nd6 Nf3+ 4.Kh1 Rxc2 5.Qxc2 +- (10.91) Depth: 6/24 00:00:01 128kN 1.Qf5 Qe5 +- (11.16) Depth: 7/24 00:00:01 184kN 1.Qf5 Qe5 2.Rxe5 Nxe5 3.Nd6 Nf3+ 4.Kh1 Rxc2 5.Qxc2 Nd4 +- (11.18) Depth: 7/26 00:00:01 231kN 1.Qf5 Qe5 +- (11.43) Depth: 8/28 00:00:01 361kN 1.Qf5 Qe5 +- (11.93) Depth: 8/28 00:00:01 375kN 1.Qf5 Qe5 2.Rxe5 Nxe5 3.Nd6 Rxc2+ 4.Qxc2 Rb8 5.Qc3 Nc4 6.Nf5 Rg8 7.Bf6 Rc8 8.Bxg7+ +- (13.71) Depth: 8/28 00:00:02 497kN 1.Qf5 Qe5 +- (13.96) Depth: 9/28 00:00:03 699kN 1.Qf5 Qe5 +- (14.46) Depth: 9/28 00:00:03 760kN 1.Qf5 Qd5 +- (14.46) Depth: 9/28 00:00:04 1098kN 1.Qf5 Qd5 +- (14.21) Depth: 10/32 00:00:05 1508kN 1.Qf5 Qd5 2.Rxe8+ Rxe8 3.Qxd5 Ne3 4.Qd3 Nxf1+ 5.Qxf1 Rc8 6.Nc5 h6 +- (14.21) Depth: 10/34 00:00:06 1810kN 1.Qf5 Qd5 +- (14.46) Depth: 11/34 00:00:07 2484kN 1.Qf5 Qd5 +- (14.96) Depth: 11/34 00:00:08 2633kN 1.Qf5 Qd5 2.Rxe8+ Rxe8 3.Qxd5 Ne3 4.Qd3 Nxf1+ 5.Qxf1 Bc7 6.Qf7 Rc8 7.Bf6 Bxg3+ 8.Kxg3 gxf6 9.Nxf6 +- (15.65) Depth: 11/34 00:00:08 3220kN 1.Qf5 Qd5 +- (15.90) Depth: 12/36 00:00:10 4356kN 1.Qf5 Qd5 +- (16.40) Depth: 12/36 00:00:10 4773kN 1.Qf5 Qe5 +- (16.40) Depth: 12/36 00:00:16 8708kN 1.Bf6 +- (16.41) Depth: 12/38 00:00:19 10393kN 1.Bf6 +- (16.76) Depth: 12/38 00:00:19 10484kN 1.Bf6 Qf2+ 2.Nxf2 Rxe7 +- (#155) Depth: 12/40 00:00:21 11380kN 1.Bf6 Rxe7 2.Bxd4 Rec7 3.Bxg7+ Rxg7 +- (#153) Depth: 13/40 00:00:23 11777kN 1.Bf6 Rxe7 2.Bxd4 Rce8 3.Qf5 Kg8 +- (#150) Depth: 14/40 00:00:25 12269kN 1.Bf6 Rxe7 2.Bxd4 Rg8 3.Ng5 Ne5 4.Bxe5 Bg1+ 5.Kxg1 Rge8 +- (#12) Depth: 15/43 00:00:48 26095kN 1.Bf6 Rxe7 2.Bxd4 Rg8 3.Ng5 Bxd4 4.Qh5 Bg1+ 5.Kxg1 g6 6.Nf7+ Rxf7 +- (#150) Depth: 16/43 00:00:50 26376kN 1.Bf6 Rxe7 2.Bxd4 Rg8 3.Ng5 Bxd4 4.Qh5 Bg1+ 5.Kxg1 g6 6.Nf7+ Rxf7 7.Rxf7 Rg7 8.Rf8+ Rg8 9.Bxg6 Kg7 10.Qxh7+ Kxf8 11.Qf7# +- (#11) Depth: 17/43 00:00:51 26834kN 1.Bf6 Rxe7 2.Bxd4 Rg8 3.Ng5 Ne3 4.Qh5 Nxf1+ 5.Kg2 Re2+ 6.Kxf1 Re1+ 7.Kxe1 Ba5+ 8.Kd1 Bb6 +- (#9) Depth: 18/43 00:00:51 27534kN (, 12.04.2005)
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