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Subject: Re: A bridge too far... / Another try with crafty

Author: pete

Date: 08:30:44 03/10/00

Go up one level in this thread


On March 09, 2000 at 06:22:27, Heiner Marxen wrote:

>>I am still interested though that if Bringer said mate in 18 is it sure it also
>>can reach it ?
>
>That I don't know for sure: the author of Bringer could know that.
>But I suspect that an announced mate *is* a forced mate, just the same
>way others do it, also.
>
>After 10 hours of crunching on a PIII/550 with 500MB hash table
>Chest 3.19 states "no mate in 16".  Somewhere in the search there
>have been some partial "mate in 13", so a mate in 18 appears plausible
>to me.  May be there is no shorter mate at all, which lets me wonder
>how Bringer managed to find this mate... respect.
>
>Heiner Marxen   heiner@drb.insel.de     http://www.drb.insel.de/~heiner/

As I still was curious I fed it again in crafty , this time on a faster system
with no tablebases ; the result was quite strange :

book file disabled.
pondering disabled.
playing a computer!
hash table memory = 384M bytes.
pawn hash table memory = 64M bytes.
max threads set to 4

Crafty v17.9 (4 cpus)

White(1): setboard 8/8/5p2/5p2/5P2/3p3B/5k1P/3K4 w

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

White(1): analyze
end-game phase
              clearing hash tables
              time surplus   0.00  time limit 30.00 (3:00)
         nss  depth   time  score   variation (1)
starting thread 1
starting thread 2
starting thread 3

...

         24     7:40     ++   1. Bg2!!
               24    20:41  10.11   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 d2 5. h7 Kg5 6. h8=Q Kg4 7. Qxf6
                                    Kf4 8. Kxd2 Ke4 9. Qe6+ Kd4 10. Qxf5
                                    Kc4 11. Qe5 Kb4 12. Qd5 Ka3 13. Qb5
                                    Ka2 14. Kc3
               24->  24:09  10.11   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 d2 5. h7 Kg5 6. h8=Q Kg4 7. Qxf6
                                    Kf4 8. Kxd2 Ke4 9. Qe6+ Kd4 10. Qxf5
                                    Kc4 11. Qe5 Kb4 12. Qd5 Ka3 13. Qb5
                                    Ka2 14. Kc3
bad move from hash table, ply=24
               25    49:14     ++   1. Bg2!!
         (2)   25-> 169:09  10.50   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 d2 5. h7 Kg5 6. h8=Q Kg4 7. Qxf6
                                    Kf4 8. Kxd2 Ke4 9. Qe6+ Kd4 10. Qxf5
                                    Kc4 11. Qe5 Kb4 12. Qd5 Ka3 13. Qb5
                                    Ka2 14. Kc3
               26   202:48     ++   1. Bg2!!
               26-> 311:56  10.89   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 d2 5. h7 Kg5 6. h8=Q Kg4 7. Qxf6
                                    Kf4 8. Kxd2 Ke4 9. Qe6+ Kd4 10. Qxf5
                                    Kc4 11. Qe5 Kb4 12. Qd5 Ka3 13. Qb5
                                    Ka2 14. Kc3
               27   369:56     ++   1. Bg2!!
               27   693:33  Mat150   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 Kf3 5. h7 Ke4 6. h8=Q Ke5 7. Qe8+
                                    Kd4 8. Qf7 Kc5 9. Qxf6 f4 10. Qe5+
                                    Kb6 11. Qxf4 Kb7 12. Qe4+ Kb6 13. Qe3+
                                    Ka6 14. Kd2 Ka5 15. Qh6 Kb4 16. Qh5
                                    <HT>
               27-> 846:32  Mat150   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 Kf3 5. h7 Ke4 6. h8=Q Ke5 7. Qe8+
                                    Kd4 8. Qf7 Kc5 9. Qxf6 f4 10. Qe5+
                                    Kb6 11. Qxf4 Kb7 12. Qe4+ Kb6 13. Qe3+
                                    Ka6 14. Kd2 Ka5 15. Qh6 Kb4 16. Qh5
                                    Ka3 <HT>
               28   919:01  Mat150   1. Bg2 Kxg2 2. h4 Kf3 3. h5 Kxf4 4.
                                    h6 Kf3 5. h7 Ke4 6. h8=Q Ke5 7. Qe8+
                                    Kd4 8. Qf7 Kc5 9. Qg8 f4 10. Qf8+ Kc4
                                    11. Qh8 d2 12. Kxd2 Kb5 13. Qb8+ Kc5
                                    14. Kd3 f3 15. Qc7+ Kd5 16. Qd7+ Kc5
                                    <HT>

Mate in 150 , wow :-)) .

pete



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