Computer Chess Club Archives


Search

Terms

Messages

Subject: Re KRRPKQ, KBBPKR endgames ...

Author: GuyHaworth

Date: 19:07:48 01/07/03

Go up one level in this thread



Always good to hear Marc's EGT news, and KRRPKQ is particularly intriguing.

I recall Marc's 'KBBPKR EGDB' of Dec 14, 2002 [and since the reference number of
the posting is not including _in_ the posting by the system, I can't quote that
and cite the posting more easily].

It doesn't include any line showing a 130-move 'record', so maybe I missed
another posting that Marc is referring to.  It does show a DTM=150 position
where White only restarts the move-count as it clocks up 107/107 on his move
108.

I don't know what sort of 'record' this might have been.  KRNKNN has the record
maxDTC = maxDTZ depth at 243.  Among pawnless endgames KQPKQ and KNNKP have
maxDTC = 114, and I think KQPKQ's maxDTZ is ~70, recalling Ken Thompson's
earliest work.  The maxDTZ for KNNKP is not known.

As RG has just pointed out, a DTM-minimaxing line does not say anything explicit
about the DTZ depth where DTZ == 'Depth to (move-count) Z(eroing) move'.  While
the minimaxing lines for different metrics (DTM, DTC, DTZ and DTR) often appear
to be very similar, I don't think one can make any general inferences that they
always are.

I guess we can be reasonably confident that the 6-man P-endgames are setting
maxDTZ-records, even though we don't know what maxDTZ has been in 3-5-man
P-endgames, and don't know exactly what it is in 6-man P-endgames.  Maybe this
is the record Marc is referring to.

[ Incidentally, it is I think easy enough - for a programmer, not me - to change
EN's code to the DTC instead of the DTM metric, but I don't think anyone has
done it yet.  If they have, I'm in the market for KQPKQ DTC. ]


What are the '$n' figures after some moves, btw?

g





This page took 0 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.