Author: Robert Hyatt
Date: 04:04:56 08/16/98
Go up one level in this thread
On August 15, 1998 at 20:28:11, blass uri wrote: > >On August 15, 1998 at 18:43:12, Robert Hyatt wrote: > >>On August 15, 1998 at 12:25:18, Komputer Korner wrote: >> >>>On August 15, 1998 at 11:30:45, blass uri wrote: >>> >>>> >>>>On August 15, 1998 at 10:57:03, Komputer Korner wrote: >>>> >>>>>On August 14, 1998 at 00:59:59, Kai Lübke wrote: >>>>> >>>>>>On August 13, 1998 at 22:13:24, Danniel Corbit wrote: >>>>>> >>>>>>>What is the maximum possible count for legal moves from any position in a chess >>>>>>>game? Has anyone ever calculated this? Can it be greater than 256? >>>>>> >>>>>>There are some strange positions which were posted to rgcc some time ago, >>>>>>the weirdest of them allowing something like 229 (or so) legal moves. >>>>>>I think this was the highest possible number (and is certain to crash just about >>>>>>any chess program I have). >>>>>>I suppose searching DejaNews will get you the posting. >>>>>> >>>>>>--- >>>>>>Shep >>>>>According to Ken Whyld in Chess the Records maximum mobility is: >>>>>With promoted pieces: 324 candidate moves >>>> >>>>324 is impossible >>>> >>>>An upper bound for the number of possible candidate moves: >>>>9 queens:9*27=243 >>>>2 rooks:2*14=28 >>>>2 bishops:2*13=26 >>>>2 knights and king:3*8=24 >>>>243+28+26+24=321 >>>>This upper bound cannot be achieved because at most 1 queen can have 27 options. >>>>313 is a better upper bound and it is possible to improve it >>>> >>>>>With no promoted pieces and 32 men on the board: 164 candidate moves >>>> >>>>27+28+26+24+8*4=137 >>>>(8*4 for pawns) >>>>This bound cannot be achieved >>>> >>>>Uri >>>>> >>>>>-- >>>>>Komputer Korner >>> >>>Sorry I didn't question these.He must have included fairy chess rules. Someone >>>else wrote a book listing the limits. I think the limit was 270 including >>>promotions. I can't find the book now. >>>-- >>>Komputer Korner >> >> >>this was beat to death a year or two ago in r.g.c.c or r.g.c. the max was >>something like 219 or some such number... There are realistic constraints that >>may make even this not possible, because to reach this max, one side has only >>a king, the other side has a bunch of pieces. He must not be able to capture >>the opponent's king, of course. >> >>In this case, I'd bet way less than 219... but I don't recall the discussion, >>since it isn't an issue in any of my programs, not having arrays dimensioned >>to some such limit.. >What is the practical max(If you check a big database of 1,000,000 games)? > >Uri I did this a couple of years ago when we had the discussion on r.g.c when Cray Blitz was still "active." I was curious if our 128 word limit (we were generating moves in a vector-method, and the C90/T90 has 128 word vectors) was a problem. In going thru a pretty large PGN games collection, 128 was never exceeded. But I didn't pay any attention to the max that occurred, only whether or not it would blow out our 128 word vector length. It didn't...
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