Author: Omid David Tabibi
Date: 11:21:35 01/17/03
Go up one level in this thread
On January 17, 2003 at 12:50:34, Robert Hyatt wrote:
>On January 17, 2003 at 01:20:23, Omid David Tabibi wrote:
>
>>On January 17, 2003 at 00:48:48, Robert Hyatt wrote:
>>
>>>On January 16, 2003 at 20:29:54, Omid David Tabibi wrote:
>>>
>>>>[D] 4k3/8/8/p1p1p1p1/PpPpPpPp/1P1P1P1P/8/4K3 w - - 0 1
>>>>
>>>>At the above position, some programs (e.g. Fritz, Hiarcs, Crafty) reach their
>>>>maximum depth in a second or two (see the Crafty analysis below), while others
>>>>(e.g. Tiger, Shredder) need more time as they search deeper (Tiger for example
>>>>quickly reaches depth 20, and then slowly goes deeper and deeper, see the Tiger
>>>>analysis below. For Genesis it takes about 4 minutes to reach depth 60). What is
>>>>different in the former class which enables them to quickly reach the max depth?
>>>>
>>>
>>>This is a hashing problem. There are not many unique positions, so hashing
>>>should cause the search to be very efficient... nothing but king moves helps
>>>this even more.
>>>
>>
>>There are only 16 (white) x 24 (black) x 2 (sides) = 768 unique positions. But
>>still normally you cannot retrieve everything from hash table: Let's say you
>>have a position stored in hash table with depth 30, but now you need a depth 31
>>search, so you cannot use the hash result; after the next iteration you will
>>need a result for depth 32 and so on and so on...
>>
>>Genesis gets about 30% hash hits from the above position.
>>
>>
>>>
>>>>Another interesting point is that Crafty (and many others) gradually reduce the
>>>>score as they searches deeper (in the below log you can see that at depth 47
>>>>Crafty gives the score 0), while some others like Tiger, remain with their fixed
>>>>score (-0.24 in the log below). Based on what factors is the score reduced in
>>>>Crafty?
>>>>
>>>
>>>Probably draw by repetition. The side that is behind won't move his king very
>>>far from the original square. The other side will try every possible square
>>>but after 40+ plies he runs out of new squares and the other side can force a
>>>repetition.
>>
>>If so, then why doesn't that happen with all the engines? Tiger never changes
>>the score; Genesis reached the depth 80 and never changed the score (and to the
>>best of my knowledge Genesis doesn't have any repetition detection bugs).
>>Besides, the score drop is usually gradual, not a sudden change to 0.
>
>
>Even on the next iteration many positions are still useful. Because
>transpositions let you
>hit the positions with enough draft so that they are useful...
>
>The score drop was pretty gradual. It dropped where it discovered it had to
>play sub-optimally
>to avoid the repetition, it dropped again the next iteration, and finally it saw
>"repetition is
>forced."
>
>Any time the king is trapped like that, the depth will skyrocket quickly.
Yes, that's what happening. But for the particular position above, even an 80
ply search doesn't result in score 0 in Genesis. But for the position below for
example, a score 0 is achieved at ply 29. No idea why that doesn't happen in the
above position.
[D] 4k3/p2p2p1/P2P2P1/8/2p1p3/p1P1P1p1/P5P1/4K3 w - - 0 1
Analysis by Genesis:
depth time score variation
1-> 0.00 0.12 1.e1d2
nodes 5 nps 0 q 0% hhits 0%
2-> 0.01 0.12 1.e1d2 e8d8
nodes 10 nps 1000 q 0% hhits 50%
3-> 0.01 0.12 1.e1d2 e8d8 2.d2e2
nodes 28 nps 0 q 0% hhits 82%
4-> 0.01 0.12 1.e1d2 e8d8 2.d2e2 d8e8
nodes 49 nps 0 q 0% hhits 77%
5-> 0.02 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2
nodes 113 nps 11300 q 0% hhits 93%
6 0.02 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2 e8d8
nodes 51 nps 0 q 0% hhits 92%
6-> 0.02 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2 e8d8
nodes 113 nps 0 q 0% hhits 94%
7 0.03 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2 e8d8 4.e2d2
nodes 78 nps 7800 q 0% hhits 96%
7-> 0.03 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2 e8d8 4.e2d2
nodes 179 nps 17900 q 0% hhits 97%
8 0.03 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2 e8d8 4.e2d2 d8e8
nodes 111 nps 0 q 0% hhits 97%
8-> 0.04 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1e2 e8d8 4.e2d2 d8e8
nodes 242 nps 24200 q 0% hhits 97%
9 0.04 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e2
nodes 233 nps 0 q 0% hhits 99%
9-> 0.04 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e2
nodes 447 nps 0 q 0% hhits 99%
10 0.05 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e2 e8d8
nodes 261 nps 26100 q 0% hhits 97%
10-> 0.05 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e2 e8d8
nodes 515 nps 51500 q 0% hhits 98%
11 0.06 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2
nodes 278 nps 27800 q 0% hhits 99%
11-> 0.06 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2
nodes 616 nps 61600 q 0% hhits 99%
12 0.07 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2 d8e8
nodes 348 nps 34800 q 0% hhits 100%
12-> 0.08 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2 d8e8
nodes 740 nps 37000 q 0% hhits 100%
13 0.08 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e1 e8d8 6.e1f1 d8e8 7.f1e2
nodes 823 nps 0 q 0% hhits 98%
13-> 0.09 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e1 e8d8 6.e1f1 d8e8 7.f1e2
nodes 1325 nps 132500 q 0% hhits 98%
14 0.10 0.11 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e1 e8d8 6.e1f1 d8e8 7.f1e2 e8f8
nodes 1753 nps 175300 q 0% hhits 99%
14-> 0.10 0.11 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2e1 e8d8 6.e1f1 d8e8 7.f1e2 e8f8
nodes 2614 nps 261399 q 0% hhits 99%
15 0.12 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2d1 e8d8 8.d1e2
nodes 4572 nps 228600 q 0% hhits 99%
15-> 0.13 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2d1 e8d8 8.d1e2
nodes 5200 nps 173333 q 0% hhits 99%
16 0.17 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2d1 e8d8 8.d1e2 d8e8
nodes 10281 nps 257024 q 0% hhits 100%
16-> 0.17 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2d1 e8d8 8.d1e2 d8e8
nodes 10945 nps 273625 q 0% hhits 100%
17 0.22 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2 d8e8 7.e2e1 e8d8 8.e1f1 d8e8
9.f1e2
nodes 12838 nps 256760 q 0% hhits 100%
17-> 0.23 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2 d8e8 7.e2e1 e8d8 8.e1f1 d8e8
9.f1e2
nodes 13556 nps 225933 q 0% hhits 100%
18 0.25 0.11 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2 d8e8 7.e2e1 e8d8 8.e1f1 d8c8
9.f1e2 c8b8
nodes 5889 nps 294450 q 0% hhits 100%
18-> 0.26 0.11 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2d1 e8d8 6.d1e2 d8e8 7.e2e1 e8d8 8.e1f1 d8c8
9.f1e2 c8b8
nodes 7239 nps 241300 q 0% hhits 100%
19 0.30 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2b1 e8d8 8.b1c1 d8e8
9.c1d1 e8d8 10.d1e2
nodes 10778 nps 269450 q 0% hhits 99%
19-> 0.31 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2b1 e8d8 8.b1c1 d8e8
9.c1d1 e8d8 10.d1e2
nodes 11508 nps 230160 q 0% hhits 99%
20 0.41 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2b1 e8d8 8.b1c1 d8e8
9.c1d1 e8d8 10.d1e2 d8e8
nodes 28841 nps 288410 q 0% hhits 100%
20-> 0.42 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2b1 e8d8 8.b1c1 d8e8
9.c1d1 e8d8 10.d1e2 d8e8
nodes 29571 nps 268827 q 0% hhits 100%
21 0.60 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2d1 e8d8 8.d1e2 d8e8
9.e2e1 e8d8 10.e1f1 d8e8 11.f1e2
nodes 45915 nps 253674 q 0% hhits 100%
21-> 0.60 0.12 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2d2 d8e8
5.d2c1 e8d8 6.c1c2 d8e8 7.c2d1 e8d8 8.d1e2 d8e8
9.e2e1 e8d8 10.e1f1 d8e8 11.f1e2
nodes 46645 nps 257707 q 0% hhits 100%
22 0.69 0.10 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2d2 b8a8
5.d2d1 a8b8 6.d1e1 b8c8 7.e1f1 c8d8 8.f1e2 d8c8
9.e2e1 c8b8 10.e1f1 b8c8 11.f1e2 c8b8
nodes 21571 nps 239677 q 0% hhits 100%
22-> 0.70 0.10 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2d2 b8a8
5.d2d1 a8b8 6.d1e1 b8c8 7.e1f1 c8d8 8.f1e2 d8c8
9.e2e1 c8b8 10.e1f1 b8c8 11.f1e2 c8b8
nodes 23093 nps 230930 q 0% hhits 100%
23 0.73 0.10 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2d2 b8c8
5.d2c1 c8d8 6.c1b1 d8e8 7.b1c2 e8f8 8.c2d2 f8e8
9.d2d1 e8f8 10.d1e2 f8e8 11.e2e1 e8f8 12.e1d1
nodes 8006 nps 266866 q 0% hhits 100%
23-> 0.74 0.10 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2d2 b8c8
5.d2c1 c8d8 6.c1b1 d8e8 7.b1c2 e8f8 8.c2d2 f8e8
9.d2d1 e8f8 10.d1e2 f8e8 11.e2e1 e8f8 12.e1d1
nodes 8736 nps 218400 q 0% hhits 100%
24 0.94 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2d1 e8d8 12.d1e2 d8e
nodes 56742 nps 283710 q 0% hhits 100%
24-> 0.94 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2d1 e8d8 12.d1e2 d8e
nodes 57472 nps 287360 q 0% hhits 100%
25 1.31 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e1 e8d8 12.e1f1 d8e
13.f1e2
nodes 97567 nps 262983 q 0% hhits 100%
25-> 1.32 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e1 e8d8 12.e1f1 d8e
13.f1e2
nodes 98297 nps 257997 q 0% hhits 100%
26 1.90 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e1 e8d8 12.e1f1 d8e
13.f1e2 e8d8
nodes 161921 nps 278693 q 0% hhits 100%
26-> 1.91 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e1 e8d8 12.e1f1 d8e
13.f1e2 e8d8
nodes 162651 nps 275213 q 0% hhits 100%
27 2.79 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e2 e8d8 12.e2f1 d8e
13.f1e1 e8d8 14.e1e2
nodes 236049 nps 267933 q 0% hhits 100%
27-> 2.80 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e2 e8d8 12.e2f1 d8e
13.f1e1 e8d8 14.e1e2
nodes 236779 nps 265745 q 0% hhits 100%
28 4.21 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e2 e8d8 12.e2f1 d8e
13.f1e1 e8d8 14.e1e2 d8e8
nodes 375234 nps 267641 q 0% hhits 100%
28-> 4.21 0.12 1.e1d2 e8d8 2.d2d1 d8c8 3.d1c2 c8b8 4.c2b1 b8a8
5.b1c1 a8b8 6.c1c2 b8c8 7.c2b1 c8d8 8.b1c1 d8e8
9.c1c2 e8d8 10.c2d2 d8e8 11.d2e2 e8d8 12.e2f1 d8e
13.f1e1 e8d8 14.e1e2 d8e8
nodes 375964 nps 268162 q 0% hhits 100%
29 4.41 0.00 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2b1 d8e8
5.b1c2
nodes 51071 nps 255355 q 0% hhits 100%
29-> 4.42 0.00 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2b1 d8e8
5.b1c2
nodes 52640 nps 250666 q 0% hhits 100%
30 4.42 0.00 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2b1 d8e8
5.b1c2
nodes 598 nps 0 q 0% hhits 100%
30-> 4.43 0.00 1.e1d2 e8d8 2.d2d1 d8e8 3.d1c2 e8d8 4.c2b1 d8e8
5.b1c2
nodes 1328 nps 132800 q 0% hhits 100%
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