The Tao of Sudoku or why oh why do I keep playing sudoku?
Is it just whatever makes sudoku addictive that keeps you playing or are you by chance pursuing something or improving some skill set?
I like the idea of completing most of the puzzles with no pencil marks. I don't see it happening any time soon, but occasionally I take note of minor progress.
I prefer printed puzzles, because I can work at my lousy handwriting even though I only use numbers.
Also with printed puzzles I can manually verify and check off rows, columns and 3x3 boxes as they are completed. I recently started chunking the numbers giving a name to the groups 1/2/3, 4/5/6, 7/8/9, which allows me to significantly speed up verification, its possible to see all three numbers at once without moving your eyes, its a visualization thing. I find it fascinating that with 3x3 boxes are easy, with rows a little harder, and with columns really tough!