History of sudoku
Sudoku is a logic game, first introduced in 1979 in american press entitled Number Place. Later it spread rapidly to Japan where it was simply renamed as sudoku. A few years later this remarkable puzzle became also successful in Europe when it practically overshadowed all the other logic games. There were almost no newspapers without a fresh task. Partially completed grid with nine rows and nine columns has become a global phenomenon and since 2006 annually the best puzzlers fight to become the world champion in sudoku.