Author: Steve Coladonato
Date: 04:38:19 04/23/99
Go up one level in this thread
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. 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. 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. >>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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