Author: Mark Rawlings
Date: 16:51:36 01/31/05
Go up one level in this thread
On January 31, 2005 at 19:07:51, Vincent Diepeveen wrote: >On January 31, 2005 at 17:56:09, Mark Rawlings wrote: > >>On January 31, 2005 at 04:37:52, Uri Blass wrote: >> >>>On January 30, 2005 at 21:25:09, Mark Rawlings wrote: >>> >>>>On January 30, 2005 at 13:28:17, Duncan Roberts wrote: >>>> >>>>>On January 30, 2005 at 12:53:11, Helmut Conrady wrote: >>>>> >>>>>>On January 30, 2005 at 10:56:55, Mark Rawlings wrote: >>>>>> >>>>>>>Very interesting! >>>>>>> >>>>>>>Is the KRNKNN mate in 262 still the longest tablebase mate?? >>>>>>> >>>>>>>Mark >>>>>> >>>>>>Yes these 523 plies are the longest DTM so far. I expect this record holds in >>>>>>the 6 piece endings. >>>>>> >>>>>>Helmut >>>>> >>>>> >>>>>was it always suspected, it would be the longest, or did they know only after it >>>>>was done. >>>>> >>>>>do you have any thought on longest 7 piece and how long ? >>>>> >>>>> >>>>>duncan >>>> >>>>I was always thinking that the egtbs with pawns would have the longest mates, >>>>but I guess that's not the case. >>> >>>I guess that you do not consider the 50 move rule. >>> >>>Mate in 150 moves with no pawns(6 pieces) is simply a draw if my memory is >>>correct and the same for mate in more moves. >>> >>>1.*** >>> >>>50...capture >>>51.*** >>>100...capture >>>you already have 4 pieces and it is a draw or mate in less than 50 moves(I am >>>not sure what is the longest mate but if I remember correctly it is less than 50 >>>moves). >>> >>>I am not sure what is the longest mate for every tablebase of 4 pieces and I >>>think to write a program to calculate it based on movei structure by having a >>>loop on all possible 4 piece positions and probing the tablebases. >>> >>>Knowing the correct values for every position can help me to check if I have no >>>bug in the program that probe tablebases. >>> >>>Uri >> >>Right. I was not considering the 50-move rule since the tablebases don't take >>that into account. It's really more of a theoretical topic for me. (I never did >>like the 50-move rule, since it's always possible that the rule could be >>changed.) >> >>Mark > >The rule will NEVER be changed again in FIDE, it's 50 moves and not a move more. > >There was a short lived experiment to make it 75 moves for specific endgames, >but after a few years this caused so much problems that it was changed back to >50 moves for all positions and NEVER again will get changed within FIDE. > >I remember 1 game Kroeze-Diepeveen which lasted 7.5 hours, for the dutch 'open' >championships in Dieren, a few years ago. Getting to those 50 moves just took >forever for me to draw. > >In fact i had 1 game against Victor Korchnoi too. Dead draw. After 7 hours of >play i fell asleep and blundered and he still won. That should have been a 50 >move rule game too. Too bad i blew it already after 7 hours. I had at the time >2150 as a rating so i guess he didn't like drawing me, him being a 2690+ rated >person at that time. Note i'm FM nowadays but get little chances now against >such big guys :) > >Nowadays most time controls are shorter. A 7 hour game is quite difficult to get >now. The FIDE level now is 40 moves in 2 hours + 1 in 20 + 15 or 30 minutes all. > >So a game never can last longer than 6.5 or 7 hours now. > >That's why a month ago i had a game which took 6.5 hours nearly. Very quickly i >managed to win KQKR there :) > >A year ago in KNSB i had a position which i could play on forever kind of. I had >night + 3 pawns (f,g,h) against opponent king + rook + 1 pawn (h pawn). > >50 moves is really a lot there. > >Basically i shuffled for 30 moves. > >By then his clock was so low that when i exchanged myself, he had only 2 minutes >left or so and had to move instantly. 50 moves against someone who has all time >of the world is really a lot. > >He made a mistake and lost. > >I was real happy, i played for my team and they needed that point to win the >match. Additional it is a big d***head at ICC who shouts around the biggest >nonsense there, as he can keep anonymous there. > >With such timecontrols as we have now in tournaments and the prospect that it >won't get slower, 50 moves really is a lot. > >It will never get more moves. > >Vincent I agree, 50 moves otb to play out a draw would be brutal! Mark
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