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Subject: Re: Mate in 29?

Author: Tom Brake

Date: 14:17:37 04/13/05

Go up one level in this thread


On April 13, 2005 at 14:25:51, John Merlino wrote:

>On April 13, 2005 at 12:24:40, pavel wrote:
>
>>[D] 3n4/rBp1p3/2P5/2PK4/k2N4/pp2R3/bppB2Rp/q1n1r1b1 w - - 0 1
>>
>>Mate in 29
>>M. Kwiatkowski
>>2nd Honourable Mention, The Problemist 1992
>>
>>1.Rg4 Even if it threatens two short mates, with Nxb3+ and Ne6+, it is still a
>>nice key. 1...h1Q+ 2.Nf3+ Kb5 Now the Knight and Rook each have chores, but they
>>can only do them if they work as a fine-tuned team - one of them holding the Qh1
>>at bay, while the other one does its job. 3.Rb4+ Ka5 4.Rbe4+! Now the Knight is
>>free. 4...Kb5 5.Nd4+ Ka4 6.Ne2+ Kb5 7.Nc3+ Ka5 8.Nxa2+ Why this Bishop had to go
>>will become clear later. 8...Kb5 Now it is the Rook's turn, but the Knight must
>>first unpin it. 9.Nc3+ Ka5 10.Ne2+ Kb5 11.Nd4+ Ka4 12.Nf3+! Kb5 13.Rb4+ Ka5
>>14.Rbxb3+ The reason for removing this pawn will be revealed later too, but at
>>least we understand why the Ba2 had to go - it would have pinned the Rb3.
>>14...Ka4 15.Rb4+ Ka5 16.Rbe4+! and the Knight is unpinned once more. 16...Kb5
>>17.Nd4+ Ka4 18.Ne2+ Kb5 19.Nc3+ Ka5 20.Na2+! It is a very nice feature of this
>>problem that the Knight goes back to the empty square a2 where it once captured
>>a Bishop. Now, it has to shield a3 from the Qa1. 20...Kb5 21.Ba6+ Finally, the
>>mating attack. 21...Rxa6 If 21...Kxa6, then 22.Rxa3+ (that is why Pb3 had to go
>>and Qxa3 had to be prevented) 22...Kb5 23.Nc3 mate. 22.Nc3+ Ka5 23.Ne2+ Kb5
>>24.Nd4+ Ka4 25.Nf3+! One last unpin of the Rook, and it's mate: 25...Kb5 26.Rb4+
>>Ka5 27.Rb6+ Ka4 28.Rxa6+ Kb5 29.Ra5 mate.
>>
>>http://www.xs4all.nl/~timkr/chess2/diarytxt.htm
>>
>>---------------------------------------------------------
>>
>>So far with Shredder Classic 1.2
>>
>>New game
>>3n4/rBp1p3/2P5/2PK4/k2N4/pp2R3/bppB2Rp/q1n1r1b1 w - - 0 1
>>
>>Analysis by Shredder Classic 1.2:
>>
>>1.Bxe1
>>  -+  (-31.21)   Depth: 1/8   00:00:00
>>1.Bxe1
>>  -+  (-31.21)   Depth: 1/8   00:00:00
>>1.Rg4
>>  =  (0.14)   Depth: 1/8   00:00:00
>>1.Rg4
>>  =  (0.14)   Depth: 1/8   00:00:00
>>1.Rg4 h1Q+
>>  =  (0.14)   Depth: 2/8   00:00:00
>>1.Rg4 h1Q+
>>  =  (-0.11)   Depth: 3/8   00:00:00
>>1.Rg4 h1Q+
>>  ³  (-0.61)   Depth: 3/8   00:00:00
>>1.Rg4 h1Q+ 2.Nf3+ Kb5
>>  -+  (-37.04)   Depth: 3/11   00:00:00
>>1.Bxe1
>>  -+  (-37.03)   Depth: 3/11   00:00:00
>>1.Bxe1
>>  -+  (-36.68)   Depth: 3/11   00:00:00
>>1.Bxe1 h1Q 2.Nxc2
>>  -+  (-36.16)   Depth: 3/13   00:00:00
>>1.Rxe1
>>  -+  (-36.15)   Depth: 3/13   00:00:00
>>1.Rxe1
>>  -+  (-35.80)   Depth: 3/13   00:00:00
>>1.Rxe1 e6+ 2.Rxe6 b1Q
>>  -+  (-31.69)   Depth: 3/13   00:00:00
>>1.Rxe1 e6+
>>  -+  (-32.00)   Depth: 4/16   00:00:00
>>1.Rxe1 b1Q 2.Rgxg1
>>  -+  (-32.00)   Depth: 4/16   00:00:00
>>1.Rxe1 b1Q
>>  -+  (-32.45)   Depth: 5/16   00:00:00
>>1.Rxe1 h1Q 2.Rexg1 Qh5+ 3.Rg5 Qf7+ 4.Ke4
>>  -+  (-32.79)   Depth: 5/16   00:00:00
>>1.Rxe1 h1Q 2.Rexg1 Qh5+ 3.Rg5 Qf7+ 4.Ke4 b1Q
>>  -+  (-32.79)   Depth: 6/23   00:00:00  39kN
>>1.Rg4
>>  -+  (-32.78)   Depth: 6/25   00:00:00  92kN
>>1.Rg4
>>  -+  (-32.43)   Depth: 6/29   00:00:01  102kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rg4+ Kb5 5.Rb4+ Ka5 6.Rg4+ Kb5
>>  =  (0.04)   Depth: 6/29   00:00:01  117kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.06)   Depth: 7/29   00:00:01  128kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.06)   Depth: 8/29   00:00:01  160kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.06)   Depth: 9/29   00:00:02  307kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.06)   Depth: 10/29   00:00:04  653kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.08)   Depth: 11/29   00:00:05  1744kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.10)   Depth: 12/29   00:00:08  4533kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.10)   Depth: 13/29   00:00:18  10715kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.12)   Depth: 14/29   00:00:37  23338kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.14)   Depth: 15/29   00:01:23  51452kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.14)   Depth: 16/31   00:03:20  112629kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.15)   Depth: 17/32   00:07:17  241546kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.15)   Depth: 18/35   00:15:11  507078kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.15)   Depth: 19/38   00:33:03  1090950kN
>>1.Rg4 h1Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5 4.Rbe4+ Kb5 5.Nd4+ Ka4
>>  =  (0.15)   Depth: 20/41   01:13:32  2366093kN
>>
>>(, MyTown 13.04.2005)
>
>The King cannot find this mate from the initial position because it has a search
>depth of (I think) 47 plies.
>
>So, just move the position forward to after 6.Ne2+, and The King says "Mate in
>23" in less than a second:
>
>[D]3n4/rBp1p3/2P5/2PK4/k3R3/pp2R3/bppBN3/q1n1r1bq b - - 0 6
>
>Time	Depth	Score	Positions	Moves
>0:00	1/3	0.00	903		6...Kb5 7.Nd4+
>0:00	1/4	0.00	5096		6...Kb5 7.Nd4+
>0:00	1/5	0.00	16935		6...Kb5 7.Nd4+
>0:00	1/6	0.00	50798		6...Kb5 7.Nd4+
>0:00	1/7	Mate23	163463		6...Kb5 7.Nc3+ Ka5 8.Nxa2+ Kb5
>					9.Nc3+ Ka5 10.Ne2+ Kb5 11.Nd4+
>					Ka4 12.Nf3+ Kb5 13.Rb4+ Ka5 14.Rbxb3+
>					Ka4 15.Rb4+ Ka5 16.Rbe4+ Kb5 17.Nd4+
>					Ka4 18.Ne2+ Kb5 19.Nc3+ Ka5 20.Na2+
>					Kb5 21.Ba6+ Rxa6
>0:01	1/8	Mate23	479548		6...Kb5 7.Nc3+ Ka5 8.Nxa2+ Kb5
>					9.Nc3+ Ka5 10.Ne2+ Kb5 11.Nd4+
>					Ka4 12.Nf3+ Kb5 13.Rb4+ Ka5 14.Rbxb3+
>					Ka4 15.Rb4+ Ka5 16.Rbe4+ Kb5 17.Nd4+
>					Ka4 18.Ne2+ Kb5 19.Nc3+ Ka5 20.Na2+
>					Kb5 21.Ba6+ Rxa6
>0:03	1/9	Mate23	1274599		6...Kb5 7.Nc3+ Ka5 8.Nxa2+ Kb5
>					9.Nc3+ Ka5 10.Ne2+ Kb5 11.Nd4+
>					Ka4 12.Nf3+ Kb5 13.Rb4+ Ka5 14.Rbxb3+
>					Ka4 15.Rb4+ Ka5 16.Rbe4+ Kb5 17.Nd4+
>					Ka4 18.Ne2+ Kb5 19.Nc3+ Ka5 20.Na2+
>					Kb5 21.Ba6+ Rxa6
>0:10	1/10	Mate23	3425030		6...Kb5 7.Nc3+ Ka5 8.Nxa2+ Kb5
>					9.Nc3+ Ka5 10.Ne2+ Kb5 11.Nd4+
>					Ka4 12.Nf3+ Kb5 13.Rb4+ Ka5 14.Rbxb3+
>					Ka4 15.Rb4+ Ka5 16.Rbe4+ Kb5 17.Nd4+
>					Ka4 18.Ne2+ Kb5 19.Nc3+ Ka5 20.Na2+
>					Kb5 21.Ba6+ Rxa6
>
>Also notice that The King will not report a PV longer than 31 plies, which is
>why the full mate sequence is not shown.
>
>jm

This is very odd then, as I get this from CM9K on an Athlon 64:

Time	Depth	Score	Positions	Moves
0:00	1/4	0.16	612		1.Nf3 Nf6 2.d3 d6
0:00	1/5	0.31	4009		1.e4 Nc6 2.Nf3 e5 3.d4 exd4 4.Nxd4
0:00	1/5	0.32	4754		1.Nf3 Nf6 2.d3 d5 3.Be3
0:00	1/5	0.33	5899		1.Nc3 d5 2.e4 dxe4 3.d4
0:00	1/6	0.17	9825		1.Nc3 Nc6 2.d4 d5 3.e4 dxe4
0:00	1/6	0.22	20156		1.e4 d5 2.Nc3 Nf6 3.exd5 e5
0:00	1/7	0.35	42256		1.e4 d5 2.Nc3 Nf6 3.Nxd5 Nxd5 4.exd5
					Qxd5 5.Ne2
0:00	1/8	0.33	141663		1.e4 d5 2.exd5 Nf6 3.Bb5+ Bd7 4.Nc3
					Bxb5 5.Nxb5 Nbd7
0:02	1/9	0.47	397886		1.e4 d5 2.exd5 Nf6 3.d4 e6 4.dxe6
					Bxe6 5.Nc3
----	----	----	----		----
0:00	1/3	-23.58	3320		1.Rc3 Re5+ 2.Kxe5 Bxd4+ 3.Kxd4
					h1=Q 4.Rc4+ Kb5
0:00	1/4	-24.40	29618		1.Rc3 e6+ 2.Nxe6 Re5+ 3.Kxe5 Nd3+
					4.Kd5 h1=Q
0:00	1/4	0.00	44003		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rc4+ Kb5 5.Rb4+
0:00	1/5	0.00	74005		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rc4+ Kb5 5.Rb4+
0:00	1/6	0.00	133023		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rc4+ Kb5 5.Rb4+
0:01	1/7	0.00	319562		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rc4+ Kb5 5.Rb4+
0:03	1/8	0.00	739682		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rc4+ Kb5 5.Rb4+
0:08	1/9	Mate29	2068494		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rbe4+ Kb5 5.Nd4+ Ka4 6.Ne2+ Kb5
					7.Nc3+ Ka5 8.Nxa2+ Kb5 9.Nc3+ Ka5
					10.Ne2+ Kb5 11.Nd4+ Ka4 12.Nf3+
					Kb5 13.Rb4+ Ka5 14.Rbxb3+ Ka4 15.Rb4+
					Ka5 16.Rbe4+ Kb5 17.Nd4+ Ka4 18.Ne2+
					Kb5 19.Nc3+ Ka5 20.Na2+ Kb5 21.Ba6+
					Rxa6 22.Nc3+ Ka5 23.Ne2+ Kb5 24.Nd4+
					Ka4 25.Nf3+ Kb5 26.Rb4+ Ka5 27.Rb6+
					Ka4 28.Rxa6+ Kb5 29.Ra5#
0:12	2/10	Mate29	3367414		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rbe4+ Kb5 5.Nd4+ Ka4 6.Ne2+ Kb5
					7.Nc3+ Ka5 8.Nxa2+ Kb5 9.Nc3+ Ka5
					10.Ne2+ Kb5 11.Nd4+ Ka4 12.Nf3+
					Kb5 13.Rb4+ Ka5 14.Rbxb3+ Ka4 15.Rb4+
					Ka5 16.Rbe4+ Kb5 17.Nd4+ Ka4 18.Ne2+
					Kb5 19.Nc3+ Ka5 20.Na2+ Kb5 21.Ba6+
					Rxa6 22.Nc3+ Ka5 23.Ne2+ Kb5 24.Nd4+
					Ka4 25.Nf3+ Kb5 26.Rb4+ Ka5 27.Rb6+
					Ka4 28.Rxa6+ Kb5 29.Ra5#
0:34	2/11	Mate29	9736612		1.Rg4 h1=Q+ 2.Nf3+ Kb5 3.Rb4+ Ka5
					4.Rbe4+ Kb5 5.Nd4+ Ka4 6.Ne2+ Kb5
					7.Nc3+ Ka5 8.Nxa2+ Kb5 9.Nc3+ Ka5
					10.Ne2+ Kb5 11.Nd4+ Ka4 12.Nf3+
					Kb5 13.Rb4+ Ka5 14.Rbxb3+ Ka4 15.Rb4+
					Ka5 16.Rbe4+ Kb5 17.Nd4+ Ka4 18.Ne2+
					Kb5 19.Nc3+ Ka5 20.Na2+ Kb5 21.Ba6+
					Rxa6 22.Nc3+ Ka5 23.Ne2+ Kb5 24.Nd4+
					Ka4 25.Nf3+ Kb5 26.Rb4+ Ka5 27.Rb6+
					Ka4 28.Rxa6+ Kb5 29.Ra5#



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