My puzzle of choice is the crossword, but from time to time I'll do a sudoku. I'm not what you'd call a fan of sudoku — I find them kind of boring, and I think that, unlike good crossword puzzles, they're utterly lacking in charm and cleverness. Also, I'm not that good at them. I would estimate that I successfully complete no more than half the sudoku puzzles I try, as opposed to, say, 95% of the crossword puzzles. Thankfully, I've recently developed a strategy that dramatically reduces the amount of time I spend on any given sudoku. And because I'm such a nice guy, I'm going to share it with you.
But first, we need to study this sudoku, which appeared in USA Today a week ago yesterday. As with all sudoku puzzles, the goal is to enter numbers in the grid so that the numbers 1 through 6 appear exactly once in each row, column, and 3x3 grid. One or more numbers are placed in the grid to provide clues as to the locations of the other numbers. So with that in mind, take a look at the puzzle below:
This puzzle cannot be solved. Without going into too much detail, the problem is that there's no place to put the number 6 in the sixth row, because the bottom row of the lower-left grid is already filled, and a six already appears in the top row of the lower-right grid. Hence, it's unsolvable.
At first I was sort of annoyed about it, but soon I realized that it had been a blessing in disguise. This literally impossble sudoku has revolutioned the way I approach the puzzles. Back in the old days, I would grind away at a tough sudoku for as long as it took, or until I got too frustrated to continue. But now, when I get stuck, I just assume that it's because there's a mistake in the puzzle, and I throw it away as defective. I cannot recommend this technique highly enough.