For puzzle fans who have been there, done that with straight Sudoku, Todd Neller offers an alternative. Neller, PhD '00, an associate professor of computer science at Gettysburg College in Pennsylvania, devises word-based polyomino puzzles—in which the letters in a name appear singularly in each row, column and jigsaw-piece-like region of a grid.
Neller studied artificial intelligence at Stanford after his mentor at Cornell—Devika Subramanian, PhD '89—suggested he go west for graduate study. A longtime game fan, he's done research on Clue, Risk and "the first analysis of optimal play for [the dice game] Pass the Pigs."
People are often surprised to learn that his polyomino puzzles aren't initially hand drawn. Neller wrote software that designs a random symmetric tiling of a grid. After a random answer to the puzzle is generated, the software sifts and replaces symmetric pairs of letters until a unique solution remains.
Download this and a second Stanford Sudoku, plus solutions (PDF).
