Author: jonas cohonas
Date: 13:57:30 03/16/01
Go up one level in this thread
On March 16, 2001 at 16:53:06, jonas cohonas wrote: >On March 16, 2001 at 16:02:20, John Hatcher wrote: > >>Here is a position arising from Rueben Fine's "Basic Chess Endings", No. 309b - >> >>[D]r7/4P1k1/3K4/8/8/8/8/5R2 w >> >>White wins after 1. Ra1. This solution was found instantly (of course) by both >>Wcrafty-18.6 (using Winboard) and Fritz6, both using the same 5-piece Nalimov >>tablebases. >> >>But now it gets strange. What if White temporizes first with 1. Rg1+ Kf7, >>arising at this position: >> >>[D]r7/4Pk2/3K4/8/8/8/8/6R1 w >> >>Wcrafty-18.6 instantly finds the win after 2. Rf1+ Kg7 (not 2. ...Ke8? 3. Rf8#) >>3. Ra1, transposing into the first position. However, Fritz6 doesn't see the >>win!? It's engine output reads: >> >>Analysis by Fritz 6: >> >>1. = (0.03): 10.e8R Rxe8 11.Rf1+ Kg6 12.Kd5 Kg5 13.Rf7 Rd8+ 14.Ke5 Re8+ >>2. = (0.00): 10.Re1 >>3. = (0.00): 10.Rh1 >>4. = (0.00): 10.Rd1 >>5. = (0.00): 10.Ke5 >>6. = (0.00): 10.Kd5 >> >>How can Fritz6 see the win in the first position and not see it in the second? >>The most obvious move, 2. Rf1+, isn't even listed in the engine output!? >> >>What's going on here? Can anyone duplicate this strange output? >> >>JOHN > >Deep Fritz finds it intantly >New position >r7/4Pk2/3K4/8/8/8/8/6R1 w - - >Analysis by Deep Fritz: > >2.e8Q+-- > ± (0.75) Depth: 1/3 00:00:00 >2.e8Q+-- Rxe8 > = (0.13) Depth: 1/3 00:00:00 >2.Re1! > +- (1.63) Depth: 1/4 00:00:00 >2.Re1! > +- (2.53) Depth: 1/4 00:00:00 >2.Rf1+! > +- (2.78) Depth: 1/4 00:00:00 >2.Rf1+-- > = (0.00) Depth: 2/3 00:00:00 >2.Rf1+-- > = (0.00) Depth: 2/7 00:00:00 >2.Rc1! > = (0.00) Depth: 2/7 00:00:00 >2.Rc1! Ra6+ 3.Kd5 Kxe7 > = (0.16) Depth: 2/8 00:00:00 >2.Re1! > +- (1.44) Depth: 2/8 00:00:00 >2.Re1! Ke8 > +- (1.91) Depth: 2/8 00:00:00 >2.Re1 Ke8 3.Ke6 Ra6+ 4.Kd5 > +- (1.75) Depth: 3/8 00:00:00 >2.Re1 Ke8 3.Ke6 Ra6+ 4.Kd5 > +- (1.75) Depth: 4/10 00:00:00 1kN >2.Rf1+! Kg7 > +- (#31) Depth: 4/10 00:00:00 2kN, tb=2 >2.Rf1+ Kg7 > +- (#31) Depth: 5/5 00:00:00 2kN, tb=4 > >(, MyTown 17.03.2001) New position r7/4Pk2/3K4/8/8/8/8/6R1 w - - 0 1 Analysis by Goliath Light: 2.Re1 Ra6+ ± (1.29) Depth: 6/9 00:00:00 2.Re1 Ke8 3.Ke6 Ra6+ 4.Kd5 Ra2 ± (1.17) Depth: 6/13 00:00:00 10kN 2.Re1 Ke8 3.Ke6 Ra6+ 4.Kd5 Ra2 ± (1.17) Depth: 7/13 00:00:00 25kN 2.Re1 Ke8 3.Ke6 Ra6+ 4.Kd5 Ra2 ± (1.17) Depth: 7/19 00:00:00 29kN 2.Re1 Ke8 3.Ke6 Ra6+ 4.Kd5 Ra2 ± (1.17) Depth: 8/19 00:00:00 44kN 2.Re1 Ke8 3.Re2 Ra1 4.Ke6 Rf1 ± (1.22) Depth: 8/21 00:00:00 64kN 2.Re1 Ke8 3.Re2 Ra1 4.Ke6 Rf1 ± (1.22) Depth: 9/21 00:00:00 105kN 2.Re1 Ke8 3.Re2 Ra1 4.Ke6 Rf1 ± (0.83) Depth: 9/21 00:00:00 143kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 = (0.00) Depth: 9/21 00:00:00 150kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 = (0.00) Depth: 10/21 00:00:00 301kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 = (0.00) Depth: 10/21 00:00:00 350kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 = (0.00) Depth: 11/21 00:00:00 625kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 = (0.00) Depth: 11/21 00:00:00 684kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 = (0.00) Depth: 12/21 00:00:00 1127kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 = (0.00) Depth: 12/22 00:00:00 1275kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 = (0.00) Depth: 13/24 00:00:01 2287kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 13/24 00:00:01 2545kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 14/25 00:00:02 4667kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 14/25 00:00:02 5167kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 15/27 00:00:03 9043kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 15/27 00:00:04 9969kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 16/27 00:00:07 17495kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 16/27 00:00:07 19330kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 17/29 00:00:13 34956kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 17/29 00:00:15 39568kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 18/32 00:00:25 67442kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 18/32 00:00:28 76691kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 19/32 00:00:51 136472kN 2.Re1 Ra6+ 3.Kd5 Ke8 4.Re2 Ra7 5.Kc6 Rxe7 6.Rxe7+ Kxe7 7.Kb7 Kf8 = (0.00) Depth: 19/33 00:00:58 158475kN
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