An easy soduko will be solved in < 30ms
An extra har soduko will be solved in about 30ms - 200ms depending on complexity
The algorithm first uses a "slice and dice" break attempt.
If the sudoku still is not solved it tries with an "extreme elimination" attempt.
If still not solved, the algorithm finds the 50% guessing cells and runs a matrix of
four of them. (16 guesses). In some cases less then four 50% guessing cells are found.
Then the matrix of course will be smaller.
About the author
More information about the author can be found here:
hoffa.se (in swedish)