In the past chessless period my whole family fell into sudokumania. Was introduced by my daughter. For those who don't know: Sudoku is a puzzle made up of a 9x9 grid, divided into nine 3x3 sub-grids. Ciphers 1 thru 9 have to be filled in a way that every cipher appears once and only once in any row, column and sub-grid. Some ciphers are given, the more, the easier the puzzle.
Sounds easy, but can be very tricky. Compared to chess the strategy and tactics are very simple. Just two basics to solve them all: Take any cipher and look for unique squares to fit them in. Take any square and exclude ciphers that cannot fit, until one remains, then fill it in. Take one strategy as far as you get, then switch, and vice versa.
Most sudokus published in newspapers are very simple. But my daughter bought a book where only 24 or even less ciphers are given. I started with a sudoku that was labeled as «mid-difficult». I had to try and wipe out blank three times to begin from scratch until the fourth time I managed to finish it. My daughter did it in a fraction of time, and with one try. But I am becoming better ...