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Subject: Re: Neverending story with incomplete tablebases

Author: Harald Faber

Date: 02:01:30 08/10/03

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On August 10, 2003 at 04:51:49, Uri Blass wrote:

>On August 10, 2003 at 03:43:05, Harald Faber wrote:
>
>>On August 10, 2003 at 02:24:47, Uri Blass wrote:
>>
>>>On August 09, 2003 at 19:11:16, Harald Faber wrote:
>>>
>>>>On August 09, 2003 at 05:55:43, Tony Hedlund wrote:
>>>>
>>>>>How can J8 allow game 14 to end as a draw?
>>>>
>>>>
>>>>This is no serious question, isn't it?
>>>>It has been posted and mentioned approx. 1,000,000 times. It is the problem of
>>>>incomplete tablebases. AFAIK you/SSDF uses the "Fritz Endgame Turbo". Based on
>>>>the Chessbase marketing it consists of 4 CD-roms with "the most important
>>>>endgame tablebases". Based on what you saw in this game, what many many others -
>>>>include me - have seen in similar positions, it is crap.
>>>>Let me ask you a question. If your answer is yes, do I win a price?
>>>>Here is the US-$1,000,000 question:
>>>>Are you missing at least one of these files in your tablebase-directory?
>>>>
>>>>kqbkp.nbb.emd
>>>>kqbkp.nbw.emd
>>>>kqbkn.nbb.emd
>>>>kqbkn.nbw.emd
>>>>kqbkb.nbb.emd
>>>>kqbkb.nbw.emd
>>>>kqbkr.nbb.emd
>>>>kqbkr.nbw.emd
>>>>kqbkq.nbb.emd
>>>>kqbkq.nbw.emd
>>>>
>>>>
>>>>If you had them all(!), Junior 8 would have mated.
>>>
>>>Did you look at the game?
>>
>>
>>Uri,
>>how else would I know of the concretely missing tablebases?
>>BTW I expand my list with kqkpp.nbb.emd and kqkpp.nbw.emd. ;-)
>>See the reason below. ;-)
>>
>>
>>>Junior8 blundered in a position when there were 6 pieces in the board
>>>and there was no winning capture that leads directly to tablebase position
>>>(the only possible capture in the game QxP could lead to a draw and Junior8 did
>>>not draw because of playing it)
>>
>>
>>OK, Uri, the great "non-believer".
>>I loaded this game into MY Junior 8. Guess what?
>>Plays: 89.Be5 #7/8.
>>Shall I post the mate lines MY Junior with ALL 5-man plays?
>>A) 89...Kh7 90.Qxg7#
>>B) 89...Kh6 90.Qxg7+ Kh5 91.Bf6 e5 92.Qg5#
>>C) 89...Kh5 90.Qxg7 Kh4 91.Qg6 Kh3 92.Qg3#
>>D) 89...Kg5 90.Qf3
>>and now
>>1. 90...Kg6 91.Qg4+ Kh6 (91...Kf7 92.Qf4+ Ke7 93.Qg5+ Kd7 94.Qxg7+ Ke8 95.Kc6
>>Kd8 96.Qf8# etc.) 92.Qxg7+ Kh5 93.Bf6 e5 94.Qg5#
>>2. 90...Kh6 91.Qg4 g5 92.Bf6 Kg6 93.Qxg5+ Kf7 94.Qg7+ Ke8 95.Qe7#
>>3. 90...Kh4 91.Qg3+ Kh5 92.Bf4 and 93.Qg5#
>>
>>Junior 8 also plays 90.Be5+!
>>If black takes the bishop, voila! Perfect TB position kqkpp.
>>Do you NOW believe that it HAS to do with missing tablebases?
>
>I know about tablebases problem under chessbase when the interface controls the
>game and not the engine in tablebases position.
>
>My point is that in the relevant case there was no 5 piece tablebases position
>so the interface never took control.
>
>This was not a case when the engine got a tablebases position and could not win
>it so the problem is not missing tablebases.
>
>>
>>
>>>Here is the final position
>>>
>>>[D]2Q5/1K4p1/4pk2/8/8/8/7B/8 w - - 0 92
>>>
>>>Are you sure that the problem is a tablebases problem?
>>
>>
>>YES!!! Such games have been posted about 1,000,000 times which cannot be
>>reproduced with a COMPLETE set of tbs.
>
>I know about games when an engine got KPP vs KP but could not win because of not
>having KQP vs KP but I did not know about games when the engine never got a
>tablebases position and missed a simple win because of not having tablebases(I
>am talking about a simple win and missing some transition to a tablebases
>position that is not trivial to win without tablebases is not defined by me as a
>simple win)
>>
>>
>>>I think that the problem is the engine and I also do not agree that the ssdf has
>>>to give the engines all the tablebases because a good engine should know to play
>>>with part of the tablebases.
>>>
>>>Uri
>>
>>
>>Uri,
>>you have always a special own point of view, but this problem of missing
>>tablebases is not Junior-only. Maybe Tony can try some other engine on this game
>>too?!
>
>I am sure that in this case most engines will have no problem even with the same
>missing tablebases.
>
>Uri


This is what I cannot check but maybe Tony will do.
Anyway I have a completely different opinion about it than you have.



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