Author: Christophe Theron
Date: 10:50:58 08/18/00
Go up one level in this thread
On August 18, 2000 at 07:15:30, Vincent Diepeveen wrote:
>On August 18, 2000 at 02:00:59, Christophe Theron wrote:
>
>>On August 17, 2000 at 23:16:56, Vincent Diepeveen wrote:
>>
>>>On August 17, 2000 at 22:23:54, Uri Blass wrote:
>>>
>>>>On August 17, 2000 at 21:21:46, Vincent Diepeveen wrote:
>>>>
>>>>>Hello,
>>>>>
>>>>>A few years ago (about 3) i claimed that searching 18-20 ply was possible
>>>>>with huge hashtables, nullmove, a good evaluation function, and
>>>>>several billions of nodes.
>>>>
>>>>searching 18-20 plies with recursive null move pruning is possible and there is
>>>>no doubt about it.
>>>>
>>>>You may miss things because of null move.
>>>
>>>Are you referring here that i need a bunch of plies more for a few
>>>very rare positions where way more as 2 nullmoves are not enough to
>>>see the truth? Just like my program won't find that huge mate as
>>>posted a bunch of messages below?
>>>
>>>>>I was considered nuts by half of the RGCC population, because no
>>>>>branching factor was capable of being that good, when you would
>>>>>search deeper, your branching factor would NOT get under 4.0, that
>>>>>was considered impossible by a lot of people even.
>>>>>
>>>>>Obviously most people following: "i believe that i see in the ads
>>>>>or where i see the outputs from", they challenged me. Some went even
>>>>>that far and called me nuts, a liar and a frog and many other terms.
>>>>
>>>>I did not read RGCC but I believe that people called you a liar because you make
>>>>the impression that you can see everything in the next 18-20 plies except some
>>>>lines that you will look for only 14-16 plies because of null moves when the
>>>>fact is that you can miss also lines with 10 plies because you use recursive
>>>>null move pruning(I remember that this was my impression when I read your posts
>>>>here about 18-20 plies).
>>>>
>>>>I do not say that using recursive null move is wrong but your 18-20 ply search
>>>>can miss 10 plies lines(If your evaluation is good enough these lines are
>>>>usually not important but I believe that there are cases when they are
>>>>important)
>>>
>>>This is incredible hard to believe. The number of positions where
>>>3 free moves + qsearch will fail. If that fails, then there must
>>>be something really wrong in evaluation! It sure can miss things,
>>>but the alternative is to search at most 12 ply fullwidth after
>>>a full night. Give me 18-20 plies then WITH nullmove please!
>>>
>>>So a zugzwang or 2 is no problem to detect then. Apart from that, the
>>>rare times we see a zugzwang arise in a game, that's usually already
>>>seen by my double nullmove.
>>>
>>>With a material only program proof isn't hard btw for this,
>>>as you can take openingsposition where my stupid experiment played
>>>1.a3 searching 30 plies.
>>>
>>>However, the whole discussion 3 years ago,
>>>when i cannot remember any person called Uri Blass posting at that time,
>>>was not a claim of mine that chess could be solved.
>>>
>>>In contradiction!!!!!
>>>Where Jaap v/d Herik writes in the start of the 80s in "computerchess"
>>>the next quote: "when software will search 10-11 ply then no human will
>>>be able to ever beat it". I completely have said the opposite,
>>>that after a ply or 12 only evaluation matters!
>>>
>>>Nowadays i would modify that already to 10 ply, noting that in difficult
>>>openingspositions the understanding of todays chess programs is still
>>>that bad that they need a few ply more to see some consequences there,
>>>so still that 12 there as found by De Groot to be the depth where the
>>>majority of short term plans are based upon is still valid!
>>>
>>>I said this partly based upon also experiences of my draughtsprogram
>>>which already for years can search easily 25-30 ply after a night, and
>>>the only way in which we (marcel monteba and me) could improve the
>>>search was by adding knowledge. This draughts program searches fullwidth
>>>by the way, as doing nothing is usually very well. I don't need to
>>>note that it sees all tactics of world champions within flashes of
>>>seconds, where even an average but smart national player can beat it
>>>pathetically.
>>>
>>>My claim was that branching factor above 10 plies was much better as
>>>i expected it to be, because of better working of hashtables, and
>>>more efficient search by means of a better evaluation which would
>>>basically research the same tree over and over again. Basically i
>>>claimed that with the number of nodes that Deep Blue searched, one
>>>could easily build a much better quality search in software.
>>>
>>>So what you write here above : "searching 18-20 ply is without doubt
>>>possible with nullmove", that's exactly what no one dared to say 3 years
>>>ago, and i'm happy you write it here! It proves how opinions have changed,
>>>as 3 years ago NO ONE dared to say that, except me.
>>>
>>>Now i don't want to sound like a profet, but i wanted to raise this
>>>discussion a bit to show how fullwidth search has superseded by
>>>nullmove driven search, and how these programs have progressed in search
>>>the past years and now are dominating the scene, where 10 years ago
>>>Genius with a fullwidth search, a few singular extensions, pruning and
>>>a clever selective search completely dominated the world of computerchess
>>>with tactics, only losing now and then from faster machines.
>>
>>
>>
>>In my experience, Genius is one of the most complete program in term of
>>knowledge, especially in the endgame. You'll have a hard time if you try to find
>>a position that Genius does not understand when other modern programs understand
>>it.
>
>Genius sees tactical a lot indeed, but it's knowledge is really outdated.
>It's a slaughter to play against Genius nowadays as it's missing too
>much knowledge and it sure isn't good in endgame, the more boring an
>endgame is, the bigger the chance it loses it!
The only explanation I see is that we do not have the same Genius...
Christophe
>This doesn't take away it's great achievements in the past, let's
>be very clear of this. Still at blitz it's a real strong opponent.
>
>>Its search is also very good, that's true, but if Genius did not win against its
>>competition with tactics when it was the best, it would have won with better
>>knowledge anyway.
>>
>>I don't think there are any singular extensions in Genius (at least nothing that
>>goes far beyond the classical extensions that almost everybody does), and I
>>think its pruning system is one of the best ever written by a human being.
>
>Sometimes it's hard to see the difference between smart extensions.
>Can be S.E., can be other extensions as well!
>
>>I also think that its evaluation is still today one of the best.
>
>Here i disagree completely. It's evaluation is completely outdated in
>my opinion, and i see it lose game after game because of it.
>
>>But unfortunately it has big problems somewhere else and nowadays is only
>>competitive on very slow computers... Now I stop, because if I go on I fear Ossi
>>is going to cut and paste my post into his next advertisement campaign. :)
>> Christophe
>
>Oh well, genius has gotten tactical stronger, that's about it. It's
>knowledge is still from 1990 or so.
>
>Hard to make commercial for something like that.
>
>Therefore i'm interested in how Rebel is gonna do in London; whether
>it's knowledge has been worked at, because rebel 9 and 10 i didn't
>find big improvements over 8.And 8 also was i.m.h.o. not a knowledge
>break through, but a speed breakthrough.
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.