## unsolvable sudoku

Post the puzzle or solving technique that's causing you trouble and someone will help

### unsolvable sudoku

At the following site are some Sudoku puzzles which are "unsolvable"

There is only 1 solution to each but you can not solve them with any known method other than guess-and-check

bluemoose

Posts: 6
Joined: 02 December 2005

Clearly the puzzles haven't been set by a regular reader of this forum - all of them fall to forced chains, some of them to fishy cycles (i.e. forced chains tat feature just a single value). Number 7 is the most interesting.
rubylips

Posts: 149
Joined: 01 November 2005

### re: Michael Mepham's "unsolvable"

Pat (2005.Oct.11) wrote:---also see www.sudoku.Org.UK/bifurcation.htm { broken link } The "unsolvable" sudoku:
Michael Mepham wrote:The puzzles below are guaranteed to have a unique solution, but defy known logical solving methods.

rubylips wrote:
bluemoose wrote:At the following site are some Sudoku puzzles which are "unsolvable" - you cannot solve them with any known method other than guess-and-check:

All of them fall to forced chains, some of them to fishy cycles (i.e. forced chains that feature just a single value).
Number 7 is the most interesting.

in www.SuDoku.Org.UK/cgi-bin/discus/discus.cgi?pg=topics { broken link } Michael Mepham's forum,
r.e.s. has already www.sudoku.org.uk/discus/messages/6/240.html?1128900375 { broken link } commented (2005.Oct.8) on the first 3 of those puzzles:
r.e.s. wrote:The online solver at act365.com/sudoku/index.htm is quite good with forcing chains, and it solved all 3 of the "unsolvable" sudokus that you recently posted at www.sudoku.Org.UK/bifurcation.htm
- so it's not (any longer) the case that these "defy known logical solving methods".

- Pat

Pat

Posts: 3641
Joined: 18 July 2005

### Re: re: Michael Mepham's "unsolvable"

Pat wrote:---

he changed it and will follow the rules that i mut be sloved with logic.
Chessmaster

Posts: 191
Joined: 21 December 2005