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Subject: razoring in crafty version 16.9, mid 1999

Author: Vincent Diepeveen

Date: 05:20:07 08/21/02

Go up one level in this thread

On August 21, 2002 at 07:58:52, Vincent Diepeveen wrote:

needed to get more crafty versions?

That all ain't octobre 1997...

/* last modified 04/01/99 */

|                                                          |
|   now we toss in the "razoring" trick, which simply says |
|   if we are doing fairly badly, we can reduce the depth  |
|   an additional ply, if there was nothing at the current |
|   ply that caused an extension.                          |
|                                                          |
      if (depth<3*INCPLY && depth>=2*INCPLY &&
          !tree->in_check[ply] && extensions == -60) {
        register const int value=-Evaluate(tree,ply+1,ChangeSide(wtm),
        if (value+50 < alpha) extensions-=60;

>On August 20, 2002 at 17:56:42, Robert Hyatt wrote:
>>On August 20, 2002 at 07:12:16, Vincent Diepeveen wrote:
>>>On August 18, 2002 at 21:48:08, Robert Hyatt wrote:
>>>>On August 18, 2002 at 21:15:47, Vincent Diepeveen wrote:
>>>>>On August 18, 2002 at 15:08:49, Gian-Carlo Pascutto wrote:
>>>>>>On August 18, 2002 at 09:06:02, Jorge Pichard wrote:
>>>>>>>   Kasparov proved that he can defeat programs at fast time controls when he
>>>>>>>defeated Deep Thought in a game/90 two games match in 1989. This program was
>>>>>>>weaker than Deep Junior is today, as it searched well over 2,000,000 NPS, but
>>>>>>>didn't have as much chess knowledge as Deep Junior.  He also defeated Deep Blue
>>>>>>>in 1996. This program is obviously much faster than Deep Junior is today, but in
>>>>>>>my opinion Deep Junior still has more chess knowledge than Deep Blue had back in
>>>>>>>PS: It is hard to compare Deep Blue of 1997 vs Deep Junior of today, but in my
>>>>>>>opinion Deep Junior Chess Knowledge could make up for the difference of Deep
>>>>>>>Blue super calculating power of 1997.
>>>>>>How do you know all this?
>>>>>>How do you know Deep Junior has more chess knowledge?
>>>>>>I mean, we don't know what Deep Blue evaluated exactly (save a few things
>>>>>>that are published). We know *nothing* about what Deep Junior evaluates
>>>>>yes we know that. Look at the paper it describes about 40 patterns and if
>>>>>you multiply that with arrays of 64 (that's how it goes in hardware)
>>>>>and add to it piece square tables it is exactly what theydid. of course how
>>>>>well defined the patterns are is a different case.
>>>>>We can see that at the rude play very easily. Look at game 1 from 97,
>>>>>where it played manoeuvres like qa5 bc7 qc5 which even seirawan comments
>>>>>correctly in his 1997 analysis. Gnuchess accuracy it is. Very rude and
>>>>>primitive, but for a program with a leaf evaluation (even though some
>>>>>tuning by preprocessor took place) with several tens of patterns (and
>>>>>as a result of that several thousands of adjustable parameters) that
>>>>>means it was searching deeper than any program with that amount of
>>>>>knowledge in evaluation in 1997. I for sure had more in 97 (though i
>>>>>used arrays less back in 97 than i do now as i'm not hardware but
>>>>>software and L2 caches were performing bad in general back then until
>>>>>pentium pro which took a few years to adjust to) so had others, but we
>>>>>all shared that at a 200Mhz pentiumpro we searched 8-9 ply, NOT 11-12.
>>>>I'm not going to comment on the rest of your nonsensical statements, but
>>>>the above is clearly wrong and that is provable.  I played in Jakarta on
>>>>a pentium pro 200.  And _My program_ searched 11-12 plies.  I have the logs
>>>>to prove it.  And anyone that wants to download the crafty (jakarta) version
>>>>can find the same thing...
>>>>So if you are going to make statements, at _least_ verify that there is some
>>>>basis of truth to them first.  _you_ might not have been able to hit 11-12
>>>>plies on a P6/200, but I did...  And others did as well.
>>> - no checks in qsearch
>>> - forward pruning last ply which also hurted nullmove incredible
>>Don't know what you mean there.  If you are talking about razoring, it was
>>a 25% gain roughly but it was removed many years ago...
>Yes it was removed around 2000-2001 after i adviced you to remove it Bob.
>>> - no mating extensions (not solving win at chess 141 even soon which
>>>   in 1997 was a 9 ply trick for me).
>>Crafty has been solving wac141 for a long time.  The null-move mate threat
>>speeded it up a ply, maybe...
>>But that is not the point... You said "nobody got to 11-12 plies".  I got
>>to 11-12 plies.  Your statement is therefore simply false because of that.
>A dubious 11-12 ply which doesn't compare to them doesn't count.
>Look DIEP 1997 was comparable, so was gnuchess or Zarkov, so was
>The King. When forward pruning turned off (except nullmove) in the king
>from that period, neither of all the programs ever got 11-12 ply.
>We can't count an idiotic crafty version. Crafty in 1997 didn't have
>anything called 'king safety'. I remember how you did effort to prevent
>getting mated by something stupid where even diep version 1.0 didn't
>fall for at bullet search depths back then, and where crafty fell for
>even at 11-12 ply. You had a special feature at icc created to prevent
>that 'mercilous' attack even. Everyone in blitz and bullet could beat
>crafty very long period of time with just a simple king safety trick which
>even 1400 chessplayers understood. They were noplayed, censored, a special
>S list was created, anything but the king safety was fixed.
>If you run with material only, every idiot gets 11-12 ply. Now you didn't
>even get it in a legal way. You needed forward pruning for it.
>Your memory is FUCKING bad that you don't even remember when you turned
>off the forward pruning in crafty.
>>You didn't qualify the "nobody to exclude those that can't solve wac 141
>>fast enough for you or whatever."
>>>Fritz3 also got 11 ply but it was also with a lot of dubiousy.
>>>In fact some hit 15 ply as well with major forward pruning back then.
>>>But that is not a fair compare. We must compare programs that searched
>>>in the same way Bob. So not forward pruning, at most nullmove. and
>>>strong in the leaves.
>>>Crafty even today is very weak there.
>>Where does that leave _your_ program then???
>>>>>So then 11-12 wins simply. 8-9 with evaluations from that period lost
>>>>>simply. period.
>>>>>Evaluations 8-9 nowadays are a different case (extending way more nowadays
>>>>>too than in 1997 too). The evaluation of DIEP is a top grandmaster relatively
>>>>>seen when compared to 1997 where it knew shit from endgames for example.
>>>>>>As a consequence, you can't possibly support any of the claims or
>>>>>>suggestions you make.
>>>>>Yes we can. The biggest evidence is the games played. Statistical evidence
>>>>>on how programs play moves is the best. The major problem is that you need
>>>>>to invest time if your chess level is not so high to see it and even a high
>>>>>rated chessplayer who knows nothing from how chessprograms evaluate will
>>>>>completely fail here (though Seirawan came pretty far but as he was paid
>>>>>by IBM he described it in a positive way, leaving conclusions to the reader).
>>>>>We have seen some marvellous conclusions already by Uri here based upon
>>>>>logfiles from the IBM computer. From evaluation viewpoint we
>>>>>see for example from the mainlines that it gives a big bonus for a bishop
>>>>>attacking its own queen. We also see it only cares for how many squares the
>>>>>queen can go to, not caring for patterns there. Very basic things which
>>>>>were at the time very normal in gnuchess type programs.
>>>>>We also see that it knows really nothing from good/bad bishops (not
>>>>>surprising, only 1 program had in 97 this thing and it was mine). It
>>>>>simply didn't care for the center at all. This is amazing nowadays
>>>>>comercial programs *only* care for the center.
>>>>>Also its knowledge on passers was very primitif. We see for example that
>>>>>it doesn't see difference even between covered passers and very good
>>>>>blocked passers. Regrettably that didn't happen a lot on the board.
>>>>>The most amazing thing by far is its huge penalties and bonuses for a few
>>>>>king safety things. that of course led to big patzer play which is nice
>>>>>and nowadays very normal. These penalties/bonuses are in complete
>>>>>contrast to pawn structure aroudn the king. In many games we see
>>>>>major mistakes here. game 1, but if i remember well game 4 where
>>>>>deep blue castles long and then plays horrible king moves and b4 b5.
>>>>>From the many king moves in the game and in the logfiles we see clearly that
>>>>>it had a very primitif 'opponent pieces to my king' distance feature.
>>>>>I remember how DIEP back in 95,96 wanted also always ka1 because that would
>>>>>mean the king is further away from the pieces. A very basic mistake we
>>>>>still see in some engines. It is a non-preprocessor mistake obviously.
>>>>>but it doesn't take away that the pattern is a very primitive heuristic.
>>>>>nearly all kind of bad moves are explained by simple bugs in evaluation.
>>>>>100% the exact bugs gnuchess also has.
>>>>>the comparision with gnuchess is not fair, but for evaluation it sure is.
>>>>>We see that the 'new gnuchess', sorry to call it like that, zarkovx,
>>>>>is the program which when getting 10-11 ply is playing from all chess software
>>>>>nearly exactly every move which deep blue also played. don't use the
>>>>>dos-zarkov, but i mean the 4.5xx versions of zarkovx where John hardly
>>>>>nullmoves the last few plies (they take some time to get 10-12 ply,
>>>>>horrible branching factor). It makes the same weird moves, same mistakes,
>>>>>same strong moves. It is a perfect match for how deep blue played.
>>>>>A person who can't play chess at all and whose program is exactly making
>>>>>the mistakes a beginner makes when making a chess evaluation.
>>>>>Best regards,
>>>>>>All of this talk about Deep Blue this and Deep Blue that is just pure
>>>>>>bullshit. Maybe Fritz 7 would kick its ass. Maybe Fritz 7 would get
>>>>>>its ass kicked. Maybe they're about as strong. I dont care either way
>>>>>>since Deep Blue doesn't exist anymore and it certainly doesn't look as
>>>>>>if it's ever going to play again. So why care about it? Why keep making
>>>>>>totally unfounded speculations? What's the frigging point? This kind
>>>>>>of discussion comes up about once in every 2 months and there has NEVER
>>>>>>EVER come anything insightful out. Instead, a lot of people are making
>>>>>>claims or saying things that they can never ever support, or even are
>>>>>>demonstrably wrong.
>>>>>>Mention the words 'Deep' and 'Blue' to anyone who works in computer
>>>>>>chess, and all sanity suddently grinds to a halt.

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