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Subject: Re: Mate in 7 moves - double nullmove finds it

Author: Vincent Diepeveen

Date: 14:02:20 09/30/00

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On September 30, 2000 at 00:03:01, Robert Hyatt wrote:

>On September 29, 2000 at 23:07:41, Vincent Diepeveen wrote:
>
>>On September 28, 2000 at 18:10:17, Robert Hyatt wrote:
>>
>>>On September 28, 2000 at 12:04:05, Vincent Diepeveen wrote:
>>>
>>>>On September 28, 2000 at 03:10:53, Christophe Theron wrote:
>>>>
>>>>I solved it WITH nullmove turned on.
>>>
>>>I don't turn null-move off until no pieces remain, although I restrict
>>>it a bit with just one piece.  Here is my output:  (PII/400 notebook)
>>
>>that's exactly what i mean!
>>
>>i don't need those restrictions to solve this!
>
>Ah but you do.  You just have a different restriction.  You use a null-move
>to prove that a previous null-move would lead to zugzwang.  And on occasion,
>you "prove" this in an incorrect way, because the second null-move will fail
>high, where the first would also have failed high, and there is no zugzwang.

In fact diep allows more often a nullmove which saves nodes.

>So in effect, you have a 'restriction' as well...

you use for endgames with 1 piece a restriction, where i
use the general implementation of the nullmove to find zugzwangs.

So you work with 'exception implementation' where i go for the
general case.

>both seem to work... in this position...

exactly.

>
>
>>
>>>
>>>                7->   0.29  -4.57   1. Rxa6 Rg2+ 2. Kf3 Rg1 3. Kf4 Rb1
>>>                                    4. Rg6 Rxb4+ 5. Ke5
>>>                8     0.34  -4.68   1. Rxa6 Rg2+ 2. Kf3 Rg5 3. Kf4 Rg4+
>>>                                    4. Kf3 Rg7 5. Ra1+ Rg1 6. Ra6 Rb1 <HT>
>>>                8     0.35     ++   1. Re1+!!
>>>                8     0.35  Mat07   1. Re1+ Rg1 2. Rf1 Rxf1+ 3. Kxf1 a5
>>>                                    4. bxa5 b4 5. a6 b3 6. a7 b2 7. a8=Q#
>>>                8->   0.36  Mat07   1. Re1+ Rg1 2. Rf1 Rxf1+ 3. Kxf1 a5
>>>                                    4. bxa5 b4 5. a6 b3 6. a7 b2 7. a8=Q#
>>>
>>>
>>>
>>>
>>>
>>>>
>>>>>On September 27, 2000 at 10:50:45, Vincent Diepeveen wrote:
>>>>>
>>>>>>On September 27, 2000 at 04:45:38, Eduard Nemeth wrote:
>>>>>>
>>>>>>>[D]8/8/p3R3/1p5p/1P5p/6rp/5K1p/7k w - - 0 1
>>>>>>>
>>>>>>>Shredder 4 and Fritz 6a this don't find !
>>>>>>>
>>>>>>>Eduard
>>>>>>
>>>>>>Diep with adaptive double nullmove pruning finds it easily:
>>>>>>
>>>>>>00:00 28 (0) 1 -5.83 Re6-e1 Rg3-g1 Re1-e7
>>>>>>00:00 30 (0) 1 -4.73 Re6xa6
>>>>>>00:00 76 (0) 2 -4.95 Re6xa6 Rg3-g1
>>>>>>00:00 302 (0) 3 -4.75 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g1
>>>>>>00:00 809 (0) 4 -4.58 Re6xa6 Rg3-g1 Ra6-a8 Rg1-g2 Kf2-f3
>>>>>>00:00 2299 (0) 5 -4.53 Re6xa6 Rg3-g5 Ra6-a1 Rg5-g1 Ra1-a8 Rg1-g2 Kf2-f3 Rg2-g1
>>>>>>00:00 4952 (443) 6 -4.52 Re6xa6 Rg3-g5 Ra6-a1 Rg5-g1 Ra1-a6 Rg1-g2 Kf2-f3 Rg2-g5
>>>>>> Ra6-a1 Rg5-g1 Ra1-a7 Rg1-f1 Kf3-e4 Kh1-g2
>>>>>>00:00 17457 (7143) 7 -4.97 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Kf3-f4 Rg5-g1 Ra6-a2 Rg1-
>>>>>>g2
>>>>>>00:00 25462 (7420) 8 -4.58 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 Rg1-
>>>>>>b1 Ra8-d8 Rb1-b3 Kf3-f2
>>>>>>00:00 37460 (7816) 9 -4.65 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 Rg1-
>>>>>>b1 Kf3-f2 Rb1-b2 Kf2-f3 Rb2-b3 Kf3-f2
>>>>>>00:00 47849 (7967) 10 -4.49 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 Rg1
>>>>>>-g3 Kf3-f2 Rg3-g4 Ra8-a1 Rg4-g1 Ra1-a5 Rg1-g2 Kf2-f3 Rg2-g5 Ra5-a1
>>>>>>00:01 59178 (9578) 11 -4.49 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 Rg1
>>>>>>-g3 Kf3-f2 Rg3-g4 Ra8-a1 Rg4-g1 Ra1-a5 Rg1-g2 Kf2-f3 Rg2-g5 Ra5-a1
>>>>>>00:01 75500 (9982) 12 -4.49 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 Rg1
>>>>>>-g3 Kf3-f2 Rg3-g2 Kf2-f3 Rg2-g1 Kf3-f4 Rg1-e1 Ra8-g8 Re1-f1 Kf4-e5 Rf1-b1
>>>>>>00:01 119501 (14319) 13 -4.49 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 R
>>>>>>g1-g3 Kf3-f2 Rg3-g2 Kf2-f3 Rg2-g1 Kf3-f2 Rg1-b1
>>>>>>00:03 292790 (38137) 14 -4.92 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 R
>>>>>>g1-f1 Kf3-e3 Rf1-f7 Ra8-g8 Rf7-c7 Ke3-f3 Rc7-c3 Kf3-f2 Rc3-c4 Kf2-f3 Rc4xb4 Rg8-
>>>>>>b8
>>>>>>00:04 522912 (63890) 15 -5.02 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8 R
>>>>>>g1-f1 Kf3-e3 Rf1-f7 Ra8-g8 Rf7-c7 Ke3-f3 Rc7-c3 Kf3-f2 Rc3-c4 Kf2-f3 Rc4-c3
>>>>>>00:08 1121847 (89898) 16 -5.65 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8
>>>>>>Rg1-f1 Kf3-e3 Rf1-f7 Ra8-g8 Rf7-c7 Ke3-f3 Rc7-c3 Kf3-f2 Rc3-c4 Kf2-f3 Rc4xb4 Rg8
>>>>>>-e8 Rb4-b3 Kf3-f2 Rb3-b2 Kf2-f3 Rb2-b1 Re8-d8
>>>>>>00:15 2033969 (172871) 17 -5.66 Re6xa6 Rg3-g2 Kf2-f3 Rg2-g5 Ra6-a1 Rg5-g1 Ra1-a8
>>>>>> Rg1-f1 Kf3-e3 Rf1-f7 Ra8-g8 Rf7-c7 Ke3-f3 Rc7-c3 Kf3-f2 Rc3-c4 Rg8-a8 Rc4-f4 Kf
>>>>>>2-e2
>>>>>>++ e6-e1
>>>>>>00:15 2089162 (173038) 17 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:15 2098043 (173038) 18 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:16 2117322 (173800) 19 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:16 2136745 (174272) 20 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:16 2181692 (174281) 21 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:17 2240891 (174334) 22 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:17 2267612 (174522) 23 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:18 2301432 (174571) 24 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:18 2335058 (174627) 25 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:19 2414393 (174689) 26 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:20 2491663 (174752) 27 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:20 2530860 (174815) 28 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:21 2591785 (174879) 29 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:22 2663804 (174942) 30 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:23 2754707 (175006) 31 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:24 2822168 (175070) 32 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:25 2854728 (175133) 33 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:26 2915639 (175196) 34 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>>b5-b4 a5-a6 b4-b3 a6-a7 b3-b2 a7-a8Q
>>>>>>00:27 2975900 (175259) 35 MATE07 Re6-e1 Rg3-g1 Re1-f1 Rg1xf1 Kf2xf1 a6-a5 b4xa5
>>>>>
>>>>>
>>>>>
>>>>>It took you 15 seconds to solve it?
>>>>>
>>>>>I assume you were running Diep on an Apple II ? :)
>>>>>
>>>>>
>>>>>
>>>>>    Christophe



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