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Subject: Re: Testposition - Pawn Magic (Eval w/ Crafty - Attn: Bob)

Author: Slater Wold

Date: 23:57:37 08/18/01

Go up one level in this thread


On August 18, 2001 at 15:18:32, Sune Larsson wrote:

>
>  [D]8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1 b - - 0 1
>
>        Ortueta - Sanz, 1934
>
>
>  This position might prove to be a good test. Deep Fritz had some problems
>  here. Found the correct move after 13:14 with -0.28, then went green
>  after 35:39 with -2.47. PIII 800 - 64 MB Hash.
>
>  Black wins after 1.-Rxb2! 2.Nxb2 c3 3.Rxb6 c4! 4.Rb4 a5!  True Pawn Magic!!
>
>
>  Ortueta - Sanz
>  8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1 b - - 0 1
>
>  Analysis by Deep Fritz: PIII 800 Mhz
>
>
>1...Bd8 2.Rxa7 Bf6 3.Rb7 Bd4+ 4.Kf1 Rf2+ 5.Ke1 Rxg2 6.h3
>  =  (0.19)   Depth: 8/20   00:00:00  67kN
>1...Bd8 2.Rxa7 Bf6 3.Kf1 Bxb2 4.Nxb2 Rxb2 5.a4 c3 6.a5
>  =  (0.22)   Depth: 9/20   00:00:00  123kN
>1...c3!
>  =  (0.19)   Depth: 9/20   00:00:00  149kN
>1...c3! 2.bxc3 Rxa2 3.Nxb6 axb6 4.Rxb6 Ra3 5.c4
>  =  (0.06)   Depth: 9/24   00:00:00  161kN
>1...c3 2.bxc3 Rxa2 3.Nxb6 axb6 4.Rxb6 Ra3 5.c4 Rc3 6.Kf2 Rxc4
>  =  (0.06)   Depth: 10/26   00:00:00  242kN
>1...Bd8!
>  =  (0.03)   Depth: 10/27   00:00:01  382kN
>1...Bd8 2.h3 Bf6 3.Kf1 Kg6 4.Rxa7 Bxb2 5.Nxb2 Rxb2 6.a4 c3 7.a5
>  =  (-0.03)   Depth: 11/25   00:00:02  1076kN
>1...Bd8 2.h3 Bf6 3.Kf1 Kg6 4.a3 Bd4 5.g4 Rh2 6.Rxa7 Bxb2
>  =  (-0.06)   Depth: 12/27   00:00:03  2041kN
>1...Bd8 2.h3 Bf6 3.Kf1 Kg6 4.g4 Rh2 5.Rxa7 Bxb2 6.Nxb2 Rxb2 7.a4
>  =  (-0.03)   Depth: 13/28   00:00:07  4281kN
>1...Bd8 2.h3 Bf6 3.Kf1 Kg6 4.a3 a6 5.Rb6 Kf5 6.Nxc5 Bxb2 7.Rxa6
>  =  (-0.06)   Depth: 14/31   00:00:13  8712kN
>1...Bd8 2.h3 Bf6 3.Kf1 Kg6 4.a3 Bd4 5.g4 Rh2 6.Rxa7 Rxh3 7.Re7
>  =  (-0.16)   Depth: 15/32   00:00:36  23307kN
>1...Bd8 2.h3 Bf6 3.Kf1 Kg6 4.g4 Rh2 5.Rxa7 Bxb2 6.Nxb2 Rxb2 7.Ra6+
>  =  (-0.16)   Depth: 16/34   00:01:27  56494kN
>1...c3!
>  =  (-0.19)   Depth: 16/34   00:01:33  60739kN, tb=4
>1...c3 2.bxc3 Rxa2 3.Nxb6 axb6 4.Rxb6 Ra3 5.c4 Rc3 6.Kf2 Rxc4 7.Re6
>  =  (-0.19)   Depth: 17/37   00:02:08  84446kN, tb=19
>1...c3 2.bxc3 Rxa2 3.Nxb6 axb6 4.Rxb6 Ra3 5.c4 Rc3 6.Kf2 Rxc4 7.Re6
>  =  (-0.22)   Depth: 18/36   00:04:21  173788kN, tb=70
>1...Bd8!
>  =  (-0.25)   Depth: 18/37   00:11:10  443095kN, tb=84
>1...Rxb2!
>  ³  (-0.28)   Depth: 18/38   00:13:14  527020kN, tb=84
>1...Rxb2! 2.Nxb2 c3 3.Rxb6 c4 4.Rb4 a5 5.Rb5 c2 6.Kf2 c1Q 7.Ke2
>  -+  (-2.47)   Depth: 18/38   00:35:39  1415072kN, tb=108
>
>(Larsson, KIL 18.08.2001)


hash table memory = 48M bytes.
pawn hash table memory = 10M bytes.
5 piece tablebase files found
20386kb of RAM used for TB indices and decompression tables
EGTB cache memory = 16M bytes.


Crafty v18.10 (1 cpus)

White(1): force
White(1): setboard 8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1 b - - 0 1

       +---+---+---+---+---+---+---+---+
    8  |   |   |   |   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    7  | *P| R |   |   |   |   | *P| *K|
       +---+---+---+---+---+---+---+---+
    6  |   | *B|   |   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    5  |   |   | *P|   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    4  | N |   | *P|   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    3  |   |   |   |   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    2  | P | P |   | *R|   |   | P | P |
       +---+---+---+---+---+---+---+---+
    1  |   |   |   |   |   |   | K |   |
       +---+---+---+---+---+---+---+---+
         a   b   c   d   e   f   g   h

Black(1): name Administrator
Crafty 18.10 vs Administrator
Black(1): time 180000
time remaining:  30:00 (crafty).
Black(1): otim 180000
time remaining:  30:00 (opponent).
Black(1): go
end-game phase
              clearing hash tables
              time surplus   0.00  time limit 30:00 (15:00)
         nss  depth   time  score   variation (1)
                7     0.19   0.50   1. ... Bd8 2. Rxa7 Bf6 3. Rf7 Bxb2
                                    4. Nxb2 Rxb2 5. a4
                7->   0.20   0.50   1. ... Bd8 2. Rxa7 Bf6 3. Rf7 Bxb2
                                    4. Nxb2 Rxb2 5. a4
                8     0.34   0.26   1. ... Bd8 2. Rxa7 Bf6 3. Rb7 Bd4+
                                    4. Kf1 Rf2+ 5. Ke1 Rxg2 6. h4
                8->   0.42   0.26   1. ... Bd8 2. Rxa7 Bf6 3. Rb7 Bd4+
                                    4. Kf1 Rf2+ 5. Ke1 Rxg2 6. h4
                9     0.67   0.01   1. ... Bd8 2. Rxa7 Bf6 3. Rb7 Bd4+
                                    4. Kf1 Rf2+ 5. Ke1 Rxg2 6. h4 Rf2
                9->   0.81   0.01   1. ... Bd8 2. Rxa7 Bf6 3. Rb7 Bd4+
                                    4. Kf1 Rf2+ 5. Ke1 Rxg2 6. h4 Rf2
               10     1.53   0.04   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 a6 5. Ke1 Rh2 6. Rb6
               10->   1.97   0.04   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 a6 5. Ke1 Rh2 6. Rb6
               11     3.50  -0.07   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    Rxa7 Rf2+ 5. Ke1 Rxg2 6. Rb7 Rh2 7.
                                    Rb5
               11->   4.08  -0.07   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    Rxa7 Rf2+ 5. Ke1 Rxg2 6. Rb7 Rh2 7.
                                    Rb5
               12     7.09  -0.09   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Rf2+ 5. Ke1 Rh2 6. Rxa7 Bxb2 7.
                                    Nxb2 Rxb2 8. Ra5 <HT>
               12->   8.29  -0.09   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Rf2+ 5. Ke1 Rh2 6. Rxa7 Bxb2 7.
                                    Nxb2 Rxb2 8. Ra5 <HT>
               13    18.58  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Kg6 5. a3 Rf2+ 6. Ke1 Rh2 7. g4
                                    a6 8. Rb6+ Kg5
               13->  21.90  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Kg6 5. a3 Rf2+ 6. Ke1 Rh2 7. g4
                                    a6 8. Rb6+ Kg5
               14    43.61  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 Rh2 5. Rxa7 Bxb2 6. Nxb2 Rxb2 7.
                                    Ra5 c3 8. Rxc5 c2 9. a4
               14->  51.39  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 Rh2 5. Rxa7 Bxb2 6. Nxb2 Rxb2 7.
                                    Ra5 c3 8. Rxc5 c2 9. a4
               15     2:41  -0.36   1. ... Bd8 2. Kf1 Bf6 3. h4 Bxh4 4.
                                    Rxa7 c3 5. Nxc3 Rf2+ 6. Kg1 Rxb2 7.
                                    Rc7 Bf6 8. Ne4 Bd4+ 9. Kf1 Rxa2 10.
                                    Nxc5 Bxc5 11. Rxc5
               15     3:33     ++   1. ... Rxb2!!
         (2)   15->   5:02  -0.75   1. ... Rxb2
               16     6:32     ++   1. ... Rxb2!!
Black(0): ?
              time=10:10  cpu=99%  mat=0  n=507729008  fh=16%  nps=831k
              ext-> chk=47370576 cap=408675 pp=1112610 1rep=2420213 mate=67061
              predicted=0  nodes=507729008  evals=94120254
              endgame tablebase-> probes done=117  successful=117
              hashing-> trans/ref=15%  pawn=7%  used=99%
              SMP->  split=0  stop=0  data=0/64  cpu=10:10  elap=10:10
Black(1): Rxb2

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

max threads set to 2
hash table memory = 48M bytes.
pawn hash table memory = 10M bytes.
5 piece tablebase files found
20386kb of RAM used for TB indices and decompression tables
EGTB cache memory = 16M bytes.


Crafty v18.10 (2 cpus)

White(1): force
White(1): setboard 8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1 b - - 0 1

       +---+---+---+---+---+---+---+---+
    8  |   |   |   |   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    7  | *P| R |   |   |   |   | *P| *K|
       +---+---+---+---+---+---+---+---+
    6  |   | *B|   |   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    5  |   |   | *P|   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    4  | N |   | *P|   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    3  |   |   |   |   |   |   |   |   |
       +---+---+---+---+---+---+---+---+
    2  | P | P |   | *R|   |   | P | P |
       +---+---+---+---+---+---+---+---+
    1  |   |   |   |   |   |   | K |   |
       +---+---+---+---+---+---+---+---+
         a   b   c   d   e   f   g   h

Black(1): name Administrator
Crafty 18.10 vs Administrator
Black(1): time 180000
time remaining:  30:00 (crafty).
Black(1): otim 180000
time remaining:  30:00 (opponent).
Black(1): go
end-game phase
              clearing hash tables
              time surplus   0.00  time limit 30:00 (15:00)
         nss  depth   time  score   variation (1)
starting thread 1
                7->   0.13   0.50   1. ... Bd8 2. Rxa7 Bf6 3. Rf7 Bxb2
                                    4. Nxb2 Rxb2 5. a4
                8     0.19   0.26   1. ... Bd8 2. Rxa7 Bf6 3. Rb7 Bd4+
                                    4. Kf1 Rf2+ 5. Ke1 Rxg2 6. h4
                8     0.24  -0.12   1. ... Rxb2 2. Nxb2 c3 3. Nd3 c4+ 4.
                                    Rxb6 axb6 5. Nf4 b5
         (3)    8->   0.24  -0.12   1. ... Rxb2 2. Nxb2 c3 3. Nd3 c4+ 4.
                                    Rxb6 axb6 5. Nf4 b5
                9     0.24     --   1. ... Rxb2
         (2)    9     0.27   0.67   1. ... Rxb2 2. Nxb2 c3 3. Rxb6 axb6
                                    4. Nd3 Kg6 5. a4 Kf5
                9     0.38     ++   1. ... Bd8!!
                9     0.61   0.10   1. ... Bd8 2. Kf1 Bf6 3. Rxa7 Bxb2
                                    4. Nxb2 Rxb2 5. a4 Ra2 6. a5
                9->   0.69   0.10   1. ... Bd8 2. Kf1 Bf6 3. Rxa7 Bxb2
                                    4. Nxb2 Rxb2 5. a4 Ra2 6. a5
               10     1.07   0.04   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 Rh2 5. Ke1 a6 6. Rb6
               10->   1.29   0.04   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 Rh2 5. Ke1 a6 6. Rb6
               11     2.21  -0.07   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    Rxa7 Rf2+ 5. Ke1 Rxg2 6. Rb7 Rh2 7.
                                    Rb5
               11->   2.55  -0.07   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    Rxa7 Rf2+ 5. Ke1 Rxg2 6. Rb7 Rh2 7.
                                    Rb5
               12     5.16  -0.09   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Rf2+ 5. Ke1 Rh2 6. Rxa7 Bxb2 7.
                                    Nxb2 Rxb2 8. Ra5 <HT>
               12->   5.88  -0.09   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Rf2+ 5. Ke1 Rh2 6. Rxa7 Bxb2 7.
                                    Nxb2 Rxb2 8. Ra5 <HT>
               13    13.55  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Kg6 5. a3 Rf2+ 6. Ke1 Rh2 7. g4
                                    a6 8. Rb6+ Kg5
               13->  15.30  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Kg6 5. a3 Rf2+ 6. Ke1 Rh2 7. g4
                                    a6 8. Rb6+ Kg5
               14    25.68  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 Rh2 5. Rxa7 Bxb2 6. Nxb2 Rxb2 7.
                                    Ra5 c3 8. Rxc5 c2 9. a4
               14->  29.54  -0.17   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g4 Rh2 5. Rxa7 Bxb2 6. Nxb2 Rxb2 7.
                                    Ra5 c3 8. Rxc5 c2 9. a4
               15     1:25  -0.25   1. ... Bd8 2. Kf1 Bf6 3. h3 Bd4 4.
                                    g3 Rf2+ 5. Ke1 Rf3 6. Rxa7 Rxg3 7.
                                    Rf7 Rg2 8. Kd1 Bxb2 9. Nxc5
               15     1:52     ++   1. ... Rxb2!!
               15     3:19  -1.93   1. ... Rxb2 2. Nxb2 c3 3. Rxb6 c4 4.
                                    Rb4 a5 5. Rb5 c2 6. g4 c1=Q+ 7. Kg2
                                    c3 8. Rh5+ Kg6 9. Nc4 Qc2+ 10. Kf3
                                    Qxa2 11. Nxa5
         (2)   15->   3:19  -1.93   1. ... Rxb2 2. Nxb2 c3 3. Rxb6 c4 4.
                                    Rb4 a5 5. Rb5 c2 6. g4 c1=Q+ 7. Kg2
                                    c3 8. Rh5+ Kg6 9. Nc4 Qc2+ 10. Kf3
                                    Qxa2 11. Nxa5
Black(0): ?
              time=4:02  cpu=210%  mat=0  n=368346060  fh=89%  nps=1521k
              ext-> chk=23467910 cap=366896 pp=962906 1rep=1135472 mate=77247
              predicted=0  nodes=368346060  evals=95924812
              endgame tablebase-> probes done=110  successful=110
              hashing-> trans/ref=34%  pawn=7%  used=99%
              SMP->  split=1510  stop=212  data=9/64  cpu=8:29  elap=4:02
Black(1): Rxb2
              time used:   4:02

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Bob, is there anyway to speed this up?  Granted, Deep Fritz would have to have
10x this hardware to find it in the amount of time Crafty did on 1 of my 1.7Ghz
CPU's, this _IS_ a pretty obvious move.

GT 2.0 and CT 14.0 both find it in less than 10 seconds on one of my 1.7Ghz
CPU's.  1:52 on 2x1.7Ghz is not good.  Deep Shredder found it on 2x1.7Ghz in
less than 30 seconds.  And well, with Deep Fritz's AWEFUL endgame, it can't find
it in any reasonable amount of time.

Do you have any ideas how you might fix this?  Or is this a problem, where any
attempt to find it faster, may result in a lowered performance elsewhere?

Thanks!


Slate

PS I got an 1800 player to look at this position on ICC, and in less than 10
seconds, he kibitzed, "Rxd2!"



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Last modified: Thu, 15 Apr 21 08:11:13 -0700

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