The Sudoku application computes the severity level of a problem on the basis of the number of occupied fields and the distribution of the pre allocations on the playing field. Furthermore the tactics necessary to solve the problem are taken into account. The computed values are standardized on the range from 0 to 100 and assigned then to the four different severity levels ("trivial" < 10, "easy" < 27, "intermediate" < 60, and "hard" for all the rest). The info box, which can be called with the help of the function key <F8>, displays both the severity level and the internal numeric value. Problems with the severity levels "trivial" and "easy" can be completely solved without backtracking, i.e. at any time there is at least one cell which has a definite assignment. However, it might happen that a problem which is very easy to solve for somebody is rated as "hard" or the other way around.