Dave, if you wish to construct a start-Sudoku from a solved one, and trace the 'strategy-level' needed, then take a look at http://users.telenet.be/Wouter.Meeussen/Sudoku.m http://users.telenet.be/Wouter.Meeussen/SudokuSolver.nb http://users.telenet.be/Wouter.Meeussen/sudoku_levels_steps.nb maybe useful, maybe not, Wouter. -----Original Message----- From: Dave Dyer Sent: Wednesday, April 11, 2012 6:22 AM To: math-fun Subject: Re: [math-fun] sudoku characteristics I'm developing a puzzle that will use solved sudoku as a starting point. My question is, looking a a solved sudoku, you can make any predictions about what kind of standard sudoku puzzles might be associated with it? For example, is there anything special about the boards that arise from the really hard puzzles, or puzzles that have unique solutions starting from very few fixed positions? _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun