Author: Steve Coladonato
Date: 10:22:48 04/23/99
Go up one level in this thread
On April 23, 1999 at 11:51:19, José de Jesús García Ruvalcaba wrote: >On April 23, 1999 at 07:38:19, Steve Coladonato wrote: > >> >>On April 22, 1999 at 19:09:57, José de Jesús García Ruvalcaba wrote: >> >>>On April 22, 1999 at 18:10:39, Steve Coladonato wrote: >>> >>>> >>>>On April 22, 1999 at 15:46:27, Jeremiah Penery wrote: >>>> >>>>>On April 22, 1999 at 14:45:19, Steve Coladonato wrote: >>>>> >>>>>> >>>>>>On April 22, 1999 at 14:26:24, Jeremiah Penery wrote: >>>>>> >>>>>>>On April 22, 1999 at 13:05:04, Steve Coladonato wrote: >>>>>>> >>>>>>>>At one time, there was a rule in chess that in the case of a known forced mate a >>>>>>>>player was allowed the standard 50 move rule or twice the number of moves with >>>>>>>>best play to execute the mate. The KNB vs K ending is a 34 move ending with >>>>>>>>best play. Therefore a player was allowed 68 moves to effect the mate. Does >>>>>>>>anyone know if this rule is still in effect? >>>>>>> >>>>>>>Can you post a position for this? The longest ending of this type that I've >>>>>>>seen is something right around 50 moves. (The losing king is in the wrong >>>>>>>corner) >>>>>> >>>>>>The 34 moves was from any position on the board. I'm sure that there are many >>>>>>positions which do not require the full 34 moves and a few which would. Which >>>>>>positions would require the 34 moves, I don't know. >>>>>> >>>>>>I haven't seen any documentation on this in recent books but back in the 70's >>>>>>there was quite a bit available. Unfortunately, I don't have any of those old >>>>>>books around. I think the basic mates were as follows: >>>>>> >>>>>>KQ v K - 9 moves >>>>>>KR v K - 12 moves >>>>>>KBB v K - 20 moves >>>>>>KNB v K - 34 moves >>>>>> >>>>>>Again, from any position on the board, mate could be accomplished within the >>>>>>number of moves above with best play. >>>>> >>>>>Ok...Perhaps you're thinking that 34 moves (68 ply) is surpassing the 50 move >>>>>rule, but it isn't. 50 moves (100 ply) is needed for that. There are no KBN >>>>>vs. K endings that take so many. >>>> >>>>Jeremiah, >>>> >>>>KarinsDad's reply to this post is correct. At one time I believe there was a >>>>rule which allowed you to exceed the 50 move rule in the case of a known forced >>>>mate where with best play twice the number of moves exceeded the 50 (100 ply). >>>>The KBN ending fits this scenario. >>>> >>> >>> The KBN vs K does not fit this scenario, as it is known that the mate can be >>>forced in less than 100 ply, when it can be forced (but the cases when it can >>>not be forced are quite simple). >>> >>The KBN v K ending is a forced mate. There are no positions where it cannot be >>forced. > > There are positions in which it can not be forced, even with the strong side to >move. Imagine the black king atacking white's knight and bishop, and the white >king far away and unable to help. Or a trapped knight in the corner, whith the >white king obstructing the white bishop. > >> It is a rather difficult mate for the average chess player and even >>when the critical postions have been learned, it would still be hard to >>accomplish the mate in 50 moves as mistakes on the winning side eat up the 16 >>moves between the 34 (33 from another post) moves required with best play and >>the 50 allowed as per the 50 move rule. >> > > I do not find difficult to deliver mate under 50 moves, even if I make some >suboptimal moves. I think I am an average player (rating 1812). > >>Just as an aside, I ran into a USCF rule book from the 60's last evening and >>they referred to a "thirty move" rule. > > What does this "thirty move" rule say? > The book was at my club's meeting hall. I'll look at it in more detail and post a follow up here. It won't be until next week though. Steve >>>>I have posted a query to the USCF concerning this. Perhaps they will be able to >>>>verify it or not. >>>> >>>>Steve
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