Sudoku And Other Big Issues

Sounds like the opening of an Alcoholics Anonymous meeting but even number puzzles can create addiction and in my case nearly did! So after about a year I quit and subsequently allow myself a once a month "drink at the trough" by doing the (usually) nice simple one in the "BIG Issue" giving myself some altruistic justification - at best, a rather weak excuse but ...

anyway there are often some good articles as well ...

For those unfamiliar with Sudoku, it has a 9 x 9 grid printed grid (like a chess board), containing 9 3 x 3 mini-grids; as presented, 17 or more numbers are given (out of 81), depending upon difficulty (roughly) and the challenge is to complete the grid within the rules; the rules are that each column and row and mini-grid shall contain all the numbers from 1 to 9.