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6-man zugzwangs ...
Posted: Sun Apr 01, 2007 10:10 pm
by guyhaw
Eiko B, with a little secretarial help from me, has surveyed all available 6-man EGTs for zugzwangs - and maxDTM positions. The results are 'in the can' and being reviewed now.
There will be 5-1 zugs (just as there are 4-1 zugs) but I doubt they can be retrieved from the FEG EGTs: a pity.
g
Posted: Fri Apr 13, 2007 9:35 am
by h.g.muller
I know little about EGTB formats used by others, but why would it be difficult to extract these zugzwangs from FEG files? Is it because you have to compare the .wtm and .btm files with swapped colors, so that the indexing is completely different for opposite sides to move?
If so, it seems not so awfully difficult to sort this out.
FEG access issues
Posted: Fri Apr 13, 2007 10:31 am
by guyhaw
I think there are two issues:
1) the index-scheme does not lend itself to 'heavy bombardment' of the EGTs in, say, search-trees. So I presume a zug-mining exercise is in the 'too inefficient' zone.
2) I don't know of any 'public' access-software of a general nature for the FEG EGTs. Only CHESSMASTER accesses them, and in its own terms.
g
Posted: Fri Apr 13, 2007 11:58 am
by h.g.muller
So if I understand you correctly the actual EGTs generated by FEG are useless to anyone except ChessMaster, as the format is not disclosed. So people generate it only for the purpose of generating the statistics file?
I was not aware of this state of affairs. This makes it all the more important to quickly provide a public source of EGTBs for unrestricted use.
Yes ...
Posted: Fri Apr 13, 2007 12:52 pm
by guyhaw
... that's my understanding too. Johan de Konig didn't wish to publish his EGT format and this is partly responsible for the non-use of FEGs outside of CHESSMASTER.
However, Marc Bourzutschky facilitated the promulgation of the 'last 16' 'Nalimov' DTM EGTs by converting his FEG EGTs to Nalimov format. So, clearly Marc cracked the code and may, or may not, have a general algorithm for converting FEG EGTs to Nalimov format - where that format is defined.
However (2), I don't think the Nalimov format for 5-1(p) EGTs _is_ defined, especially with regard to 'four like men', so there is a hiatus on the 5-1(p) EGTs. Curiously, there will be some zugs in the 5-1(p)s.
g
PS: I see I still have some scanning to do
