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Subject: Re: crafty problem (Crafty v19.19)

Author: Robert Hyatt

Date: 10:54:44 11/09/05

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On November 08, 2005 at 03:04:55, Renze Steenhuisen wrote:

>On November 08, 2005 at 01:21:03, Will Singleton wrote:
>
>>On November 07, 2005 at 17:14:45, Rob Basham wrote:
>>
>>>[D]6r1/p1pq1p1p/1p1p1Qnk/3PrR2/2n1P1PP/P1P5/4R3/6K1 w - - 0 1
>>>
>>>Well, it is easy for Fidelity Mach 3.....:-)
>>>
>>>Mach 3 at level one finds all the correct moves to this mate in 11....!
>>>
>>>Beginning with....Rh5+
>>>
>>>How does your machine do on this one...?
>>>
>>>Rob
>>
>>Oddly, Crafty 20.0 bh cannot solve this.  Bug?  does it happen in the latest
>>crafty?
>
>Can someone elaborate on what the +1, +3, and +M mean? I have no time to look
>into it in the source code. Just too lazy ...
>
>Cheers, Renze!
>                8->   1.29  -5.31   1. h5 Rxf5 2. exf5 Qd8 3. Qxd8 Rxd8
>                                    4. hxg6 fxg6 5. fxg6 Kxg6
>                9     2.25     +1   1. h5!!
>                9     3.34     +3   1. h5!!
>                9     4.81     +M   1. h5!!
>                9     9.68   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>                9->  10.74   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>               10    13.59   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>               10->  15.45   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>               11    20.39   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>               11->  22.78   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>               12    30.26   0.01   1. h5 Rxf5 2. exf5 Qd8 3. g5+ Kxh5
>                                    4. Rh2+ Kg4 5. Rg2+ Kf3 6. Rf2+ Kg3
>                                    7. Rg2+ Kf3
>               12     1:14     +1   1. Rg5!!
>               12     1:18     +3   1. Rg5!!
>               12     1:42     +M   1. Rg5!!
>               12     2:12   3.96   1. Rg5 Qxg4+ 2. Rxg4 Rge8 3. Rh2 Ne3
>                                    4. h5 Nxg4 5. hxg6+ Nxh2 6. gxf7+ Kh5
>                                    7. fxe8=Q+ Rxe8 8. Qf7+ Kg4 9. Qd7+
>                                    Kg3 10. Qxe8 Nf3+ 11. Kf1
>               12->   2:14   3.96   1. Rg5 Qxg4+ 2. Rxg4 Rge8 3. Rh2 Ne3
>                                    4. h5 Nxg4 5. hxg6+ Nxh2 6. gxf7+ Kh5
>                                    7. fxe8=Q+ Rxe8 8. Qf7+ Kg4 9. Qd7+
>                                    Kg3 10. Qxe8 Nf3+ 11. Kf1
>               13     2:34   4.15   1. Rg5 Qxg4+ 2. Rxg4 Rge8 3. Rh2 Ne3
>                                    4. h5 Nxg4 5. hxg6+ Rh5 6. Rxh5+ Kxh5
>                                    7. Qf5+ Kh6 8. gxf7 Rf8 9. Qe6+ Kg7
>                                    10. Qxg4+ Kxf7 11. Qd7+ Kg6 12. Qxc7
>               13     2:37     +1   1. Rh5+!!
>               13     2:41     +3   1. Rh5+!!
>               13     2:45     +M   1. Rh5+!!
>               13     4:38  Mat11   1. Rh5+ Rxh5 2. g5+ Rxg5+ 3. hxg5+
>                                    Kh5 4. Rh2+ Nh4 5. Qh6+ Kg4 6. Qxh4+
>                                    Kf3 7. Rf2+ Ke3 8. Qg3+ Kxe4 9. Qf3+
>                                    Ke5 10. Re2+ Ne3 11. Rxe3#
>               13->   4:40  Mat11   1. Rh5+ Rxh5 2. g5+ Rxg5+ 3. hxg5+
>                                    Kh5 4. Rh2+ Nh4 5. Qh6+ Kg4 6. Qxh4+
>                                    Kf3 7. Rf2+ Ke3 8. Qg3+ Kxe4 9. Qf3+
>                                    Ke5 10. Re2+ Ne3 11. Rxe3#


Sure.

+1 means that the score was above the fairly narrow aspiration window used at
the root of the tree.  Normally iteration N+1 uses score +/- .4 or so, where
score comes from iteration N.

The +1 means we are adding +1.0 to the upper bound and re-searching, which means
at least the score is +.4 better than expected.  The +3 means that the +1.0
search failed high as well, meaning the real score is greater than previous best
score +1.0, so now we add another +2.0 to it.  The +M means that the search
failed high on the score+3.0 search, so we are winning a piece or more.  So we
set the upper bount to +Mate and this time we are going to get a good score
back. :)




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