One Cell
Recently, I came across the book "Artisanal Sudoku". I must confess that I've been spending most of my offline time working through its puzzles. They accomplish the rare feat of being both logically approachable and aesthetically pleasing, and on multiple occasions I've found myself impressed by some more abstract realizations that I haven't seen before. I especially look forward to the final chapter, but I'm forcing myself to go in order. I think the reason I really enjoy variant sudoku and don't often enjoy classic sudoku is because classic sudoku usually isn't set with rigorous deductions in mind. I'd wager that 98% of any uniformly randomly selected classic sudoku is likely solvable with some combination of pointing sets, digits that can only go in one place because the other eight would cause repetition, and places that can only have one digit because the other eight would cause repetition. This is in stark contrast to the flexibility of vari...