CCRL Discussion Board

I would like to get in touch with Helmut Conrady if possible. He wrote a piece in Computer Schach und Spiele around 2003 I think - on the longest sequences of absolutely-unique moves for the attacker to be found in various 5-man EGTs. The most important AUWMS (Absolutely Unique Winning Move Sequence...

I presume you meant KRPPKRP rather than KRPPKPP. Yakov K and Marc B wrote an article about their sub-9-man EGT Generation, using Yakov's program. It is in "64", 2009/7 in Russian. Their previous MB/YK article on 7-man P-less EGTs was in EG Vol XI pp 493-510. They did all sub-7-man EGTs afr...

Yes: you have a study based on Noam Elkies' zugzwang position 'Z07'. Noam was focused on creating zugs of types a4-a6 rather than creating studies. Not sure what the authorship attribution should be: 'Ruiz after Elkies' I think. I'm certainly not in the back-story of your study's creation. As to its...

... #75,270 in HvdH's Endgame Study Database IV.

Thank you for highlighting that: it's very special, and dbIV/EGTs help to understand why it is so.

A combination of the Trebuchet and N-converting-P themes with a neat preamble. Excellent

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The zugzwang is a big theme in studies, and AJR used to publish lists of zugs - often in EG. Unfortunately, these lists were often found to have errors. See http://ilk.uvt.nl/icga/games/chess/endgames.php for the complete list of value-critical ('Type A') zugs. See http://centaur.reading.ac.uk/view/...

Since 'studies' and sub-7-man chess are being discussed in the same breath here ... ... I should say that I've just written a short piece for the ICGA Journal reporting the data-mining of Harold van der Heijden's excellent ENDGAME STUDY DATABASE IV. Eiko Bleicher and I evaluated all sub-7-man positi...

I have for a long time deprecated the epithet 'EGTB Study', assigned originally by John Roycroft to any study which entered the sub-7-man 'EGT'd' zone of chess. AJR seemed to be implying that such studies should not be allowed - or should be confined to their own ghetto, and that their composers wer...

DTM = 115 sounds familiar: maybe the maxDTM figure, or a position from an old KNNKP paper involving JvdH. wtm draws, and indeed, btm - Black wins in DTM = 115. The DTZ50 EGT only signals a win if the defender cannot claim a 50-move draw. That's how it helps! I'll be making my holding of DTZ50 EGTs a...

The 3-man position would appear to sort minimality out - except that White would obviously play 1.h4 or 1/h3 to be really annoying. ... and you don't want to be forcing a zeroing of the move-count if you're losing, so I think the minimal position for a so-far-non-trivial-irreversible-move is still o...

We are discussing if there are any other scenarios when the ply-count can be set to zero because the last move is 'easily seen' to be irreversible. Currently only capture and P-push zero the ply-count but a move which rejects an e.p.-pawn-catpure-offer or reduces castling rights is also irreversible...

Oops - I see I filed this snippet in a new thread which was not my intention (and it can be deleted): the item was meant to be under this '50-move-rule' thread ... http://centaur.reading.ac.uk/4524/, 'Chess Endgames: 6-man data and strategy', includes the max DTZ50 position 'BB-NN' and a DTZ50-minim...

Yes, there are certainly other moves that are irreversible (other than P-push, capture, e.p.-capture rejection and castling-rights-changing moves). Your example is indeed one such - nice - however, I think it's not possible to identify all of these (or maybe any) with a simple, computer-implementabl...

KK: see http://centaur.reading.ac.uk/4524/ ... Table 5a - g

The offer of DTC and DTZ EGTs is at viewtopic.php?f=6&t=5262

The DTZ50 EGTs that I have are not there yet. g

... 'posts where cetrain endgame tablebase generators say ...' Do you have any specific, accurate references to these? What generators are out there, not including - please - the overly-inscrutable 'Skipper_NORTON'. I take it they do not include Nalimov, not geared for multi-core, FEG (ditto), Konov...

Marc' 'showed' everyone inteested the result - in that it was communicated by the relevant forums on or before 26th May 2006, q.v. e.g. http://www.xs4all.nl/~timkr/chess2/diary_16.htm

g

Ed: I think you are beginning to sound like an overclocking/fridge salesman rather than an endgame enthusiast - so maybe this is the wrong place for this duscussion. Obviously, if you can turn the clock up, you will lessen the 'CPU bottleneck' if there is one. But if you are creating n-man EGTs and ...

Consideration of a k-ply rule, and the 50-move rule in particular, does touch on a number of themes, some mentioned above. First, Checkers and even more so, Chinese Chess do seem to be afflicted by rules which call on the judgement of an arbiter who - at the top level of the game when these rules ar...

There seems little point in investing in cutting-edge processors to generate EGTs when the activity is essentially I/O limited. Even less argument for 'pushing the envelope' in the old direction of single-processor speed when the cooling technology brings its own risks and the industry is moving the...

If JS is referring to my paer on '6-man Chess and Zugzwangs', the 5-1 zugs were supplied by Marc B after a search of EGTs created by him using Yakov Konoval's code. '6-man' should strictly have been 'Sub-7-man' but no-one's perfect. There are sets of KNPPK and KNPPPK zugs, and and a challenge is to ...

Apologies - I perhaps did not make myself clear. After Eiko B ran all sub-7-man mainline positions in HHdbIII past his copy of the Nlalimov EGTs, I analysed the findings and sent all the information about EGT-faulted studies and wrong-value-positions to Harold van der Heijden. He incorporated almost...

Harold van der Heijden is one of the leading lights in the Study Community and has worked tirelessly on its behalf as EG editor, composer, judge and database compiler. His 'HHdbIV' database has no rival and now accounts for over 76,000 of the surmised 90,000 studies thought to have been published q....

Draws do not have a depth in the DTM (depth to mate) metric. However they _might_ have a depth in the DTZ (depth to move-count zeroing move) or even DTC (depth to conversion and/or mate) metrics. Back as far as 2002, I certainly wanted to distinguish between draws which had DTx-depths and those that...

I have made available a complete set of sub-6-man DTC and DTZ EGTs at the following URLs: http://extra.sse.reading.ac.uk/people/G.Haworth/DTCZ_EGTs/ ... all pawnless EGTs which are both DTC and DTZ http://extra.sse.reading.ac.uk/people/G.Haworth/DTC_EGTs/ ... all Pawnful (and no P-less) DTC EGTs htt...

I haven't being paying much attention recently. Have their been developments to EGT-algorithm algorithms that significantly reduce the number of I/O disc-transfers? I conjecture that the best way to optimise is to notionally divide the index-range of positions into a number of subranges and 'park' r...