Computer Chess Club Archives




Subject: Re: a question to Tord about detecting threats in null move

Author: Uri Blass

Date: 12:08:49 10/04/03

Go up one level in this thread

On October 04, 2003 at 14:12:09, Vincent Diepeveen wrote:

>On October 03, 2003 at 17:34:56, Christophe Theron wrote:
>>On October 03, 2003 at 15:36:22, Mridul Muralidharan wrote:
>>>You misinterpreted me.
>>>On October 03, 2003 at 14:51:24, Uri Blass wrote:
>>>>On October 03, 2003 at 13:38:54, Mridul Muralidharan wrote:
>>>>>  I was a bit taken aback by these declarations :
>>>>>On October 03, 2003 at 12:47:23, Uri Blass wrote:
>>>>>>I prefer even not to care about using hash tables for pruning because my
>>>>>>experience told me that I cannot get significant gain there easily
>>>>>Hash table not giving you pruning ? I suspect a bug in your hashkey -
>>>>>Or maybe it is the easily that is operative word ?
>>>>>I think there are a lot of open source programs that you can refer to and
>>>>>correct your bugs with - crafty , GNUChess , etc , etc.
>>>>>Might help to get this right.
>>>>I do not like to copy from other sources.
>>>>I found that instability helped me to do my program significantly better.
>>>>If I delete it in order to be able to copy from other programs then I may need
>>>>to start by doing it significantly weaker.
>>>I did not mean - "copy" here.
>>>Rome was not built in a day. What I meant is :
>>>Look at their implementation - check yours. Find any obvious bugs.
>>>I seriously suspect that there are - since hashtables not only help in pruning ,
>>>but massively help in move ordering.
>>>If you can afford to make these statements - then your impl is horribly full of
>>>As far as "instability helping" - I'm really not sure what you mean by this. As
>>>far as I know - everyone , including me , tries to reduce instability so that
>>>search is more stable requiring minimal search tree.
>>>Wild extensions , unstable pruning , etc may help you in solving test suites
>>>better and faster - but in real world games , it will suck badly.
>>>>>>(I have a lot
>>>>>>of stuff that means that pruning or extension is not defined only by the
>>>>>Where ever possible , I try to make the search behaviour as relevent to the
>>>>>current position as possible and not rely on past search.
>>>>>Why do you want to do the opposite ?
>>>>because the opposite gives me some advantages.
>>>test , test , test - dont assume.
>>>like my collegue says : When you AssUMe , you make an Ass of U and Me ;)
>>>>Movei has its chances against every program inspite of having bad order of moves
>>>>and bad extensions and bad pruning.
>>>acceptance is the first step to improvement !
>>>>I believe that I can get above Crafty level if I improve order of move
>>>>extensions,pruning and evaluation.
>>>>Movei already has its chances against Crafty but today crafty is significantly
>>>>There is a lot to improve and the main problem is programming.
>>>AFAIK movei is not smp - so no point in saying search here :)
>>>SO , other than move ordering , eval and pruning : what else is left ? interface
>>>code ? ;)
>>>anyone can get to crafty level or higher - IF you are willing to put in the
>>>effort and scientifically research.
>>>All the best - wishing to see a better Movei and a more scientific Uri :)
>>You are talking without knowing Uri, obviously.
>>You are also talking about commputer chess without really knowing, I fear.
>Ugh, latest Messchess hands down kicks Movei.

I do not know the level of Messchess so I can say nothing about it.

>>Uri has been talking with us about chess programs for a long time without
>>writing one. So at the begining he came with ideas that were not really
>>relevant, or not exactly to the point.
>Lucky you didn't write that this hasn't changed yet :)

I will not respond here but I think that a lot of my ideas were to the point and
I did not implement most of them and did not discuss about them.

>>What I like about Uri is that at some point instead of keeping talking about the
>>subject he has started to write his own chess program. I also know that he has a
>>very scientific, objective approach in what he does.
>like playing without book, randomly making 1.h3 and claiming that this was ok, i
>found that a funny one :)

ok what about the game that movei beated Deep Sjeng with 1.e4 c6 2.d4 d6

Note that I do not claim that movei is at the level of the top programs and it
is going to lose most of the games against Deep Sjeng but it has chances even
with bad opening choice.

I know that you may claim that it was blitz(only 40/40 on single processor)
but the point is that there are a lot of ways to get out of the popular
lines(like 1.e4 c6 2.d4 d5) without losing the game because of book.

I do not think that 1.h3 is worse than 1.e4 c6 2.d4 d6

If you are afraid of losing games because of opening traps then prepare a small
book to get out of the popular lines.

[Event "WBEC4-1st Division"]
[Site "ATHLON-MP2200"]
[Date "2003.08.06"]
[Round "21.2"]
[White "DeepSjeng 1.5"]
[Black "Movei 0.08.068"]
[Result "0-1"]
[PlyCount "132"]
[EventDate "2003.??.??"]
[TimeControl "40/2400:0"]

1. e4 c6 2. d4 d6 3. Nc3 Nf6 4. f4 Qa5 5. Bd3 e5 6. Nf3 exd4 7. Nxd4 Be7 8. Nf3
Nbd7 9. Bd2 Nc5 10. Qe2 Qc7 11. O-O-O O-O 12. Kb1 Nxd3 13. Qxd3 b5 14. Rhe1 a5
15. Ne2 b4 16. Ned4 Ba6 17. Qe3 g6 18. a4 Rab8 19. f5 c5 20. Nb5 Bxb5 21. axb5
Rxb5 22. e5 dxe5 23. Qxe5 Rb7 24. Bg5 Qc6 25. fxg6 hxg6 26. h4 a4 27. Qf4 Nh5
28. Qc4 Bxg5 29. hxg5 b3 30. c3 Rc8 31. Rd2 Ra7 32. Ne5 Re7 33. Rd5 Rce8 34.
Rf1 Qc7 35. Nd3 Qg3 36. Rc1 Qxg2 37. Rxc5 Ng3 38. Nf4 Qd2 39. Rd5 Ne4 40. Nd3
Qg2 41. Nf4 Qf2 42. Nxg6 Re6 43. Qd4 Qxd4 44. Rxd4 fxg6 45. Rd3 Nxg5 46. Rg3
Ne4 47. Rg2 Kg7 48. Rd1 a3 49. Rd7+ Kf6 50. Rd1 Rd8 51. Rxd8 Nxc3+ 52. Kc1 Re1+
53. Kd2 axb2 54. Kxc3 b1=Q 55. Rd6+ Ke7 56. Rgd2 Re3+ 57. Kb4 Qe4+ 58. Ka5 b2
59. Rd7+ Ke6 60. R7d6+ Ke5 61. Re6+ Kxe6 62. Rxb2 Ra3+ 63. Kb6 Qd4+ 64. Kb7
Qxb2+ 65. Kc7 Rc3+ 66. Kd8 Qb8# {Movei->Black mates} 0-1

>>So if I was you I would not give Uri beginners's advices like "test, test -
>>don't assume". Because as far as I know that's exactly what he is doing.
>i doubt it ;)
>>I also believe that Uri is right in not trying to get too much inspiration from
>>other chess programs.
>Some thing tells me that certain assembly programmers are very well in debugging
>other commercial programmers software ;)
>>I think you should refrain from giving lame advices to Uri and tell us instead
>>about your achievements as a chess programmer.
>>    Christophe
>In case you missed it, Messchess is way higher rated than movei.
>However Mridul is from India, so in contradiction to you, can't afford going to
>the world champs otherwise he would have.

You may be right but what rating list are you talking about.
Movei play in a lot of tournaments of winboard program and I never saw results
of Mridul there.

Note that the programmer told me that he did not mean to offend me so there is
no problem with him.

There are problems with you because you always try to offend other people(not
only me).

>Oh another thing. He knows more about parallel searching, multithreading and
>linux kernels than you do Christophe :)
>Without Mridul, the Diep would have had severe problems getting to work as well
>as it works now at the different supercomputers. Especially that itanium2

You seem to be lucky to get support from people.
I do not understand why so many people want to help you if you try to offend
almost everybody.

One example:
You call Crafty's evaluation primitive.
What do you think that you get by doing it?

If you have better evaluation function then you can be happy with it without
insulting other people.


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