The New Sudoku Players' Forum

[bluemoose]

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

www.sudoku.org.uk/bifurcation.htm { broken link }

[rubylips]

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.

[Pat]

---also see www.sudoku.Org.UK/bifurcation.htm { broken link } The "unsolvable" sudoku:

The puzzles below are guaranteed to have a unique solution, but defy known logical solving methods.

At the following site are some Sudoku puzzles which are "unsolvable" - you cannot solve them with any known method other than guess-and-check:
www.sudoku.org.uk/bifurcation.htm { broken link }

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:

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

[Chessmaster]

---

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