colonel@sunybcs.UUCP (George Sicherman) (10/15/83)
In backgammon even an innocent-looking position may contain a pitfall. Ask yourself how you would play 6-4 in this position--then ask a computer program the same question! | O |BAR| | O O O O |BAR| +------------------ 1 3 5 6 George Sicherman ...seismo!rochester!rocksvax!sunybcs!colonel
colonel@sunybcs.UUCP (George Sicherman) (10/15/83)
In backgammon even the simplest of positions may contain pitfalls. Ask yourself how you would play 6-4 in this position--then ask a computer program the same question! | 0 |BAR| | 0 0 0 0 |BAR| +-------------+---+-- 1 2 3 4 5 6 George Sicherman ...seismo!rochester!rocksvax!sunybcs!colonel
israel@umcp-cs.UUCP (10/18/83)
I don't understand. When I learned to play backgammon, I was told that you can't use a number as a smaller number if you can use the whole thing. In other words, I can't use a four to bear a man off of the two point if I can move a man from the five point to the one point. If that is true, then a 6-4 in this situation: | 0 |BAR| | 0 0 0 0 |BAR| +-------------+---+-- 1 2 3 4 5 6 is predetermined (i.e. use the six to bear the man on the six point off) and then use the four to move the man from the five point to the one point. Have I been playing under the wrong rules all these years, or am I just missing something in the problem description? -- ~~~ Bruce ~~~ Computer Science Dept., University of Maryland {rlgvax,seismo}!umcp-cs!israel (Usenet) israel.umcp-cs@CSNet-Relay (Arpanet)
woods@hao.UUCP (Greg Woods) (10/24/83)
> In backgammon even an innocent-looking position may > contain a pitfall. Ask yourself how you would play > 6-4 in this position--then ask a computer program > the same question! > > | O |BAR| > | O O O O |BAR| > +------------------ > 1 3 5 6 ----------------------------------------------------------------------------- Obviously, the first reaction would be to say you have to pull off the six and move the piece on 5 to 1. However, this leaves O | O |BAR| | O O |BAR| +------------------ 1 3 5 6 and if you now roll a 2-1 (only a 1/18 chance, but still) it will take you 3 turns to get all your pieces off. However, it is legal to move the piece on six to two, and then use the 6-roll to bear off the piece from 5. This leaves: | O |BAR| | O O O |BAR| +------------------ 1 3 5 6 now you would have to roll 2-1 2 consecutive times, a 1/324 chance, not to get all your pieces off in 2 turns. Therefore, the latter is the superior move. I'll bet that's what the program did! GREG -- {ucbvax!hplabs | allegra!nbires | decvax!brl-bmd | harpo!seismo | ihnp4!kpno} !hao!woods