DC Sudoku

The Puzzle Rating System ...

... is very simple:

# of Tiles Given Rating

35 or more:
31 to 35:
28 to 30:
26 or 27:
25 or less: Beginner
Easy
Medium
Hard
Expert

Reasoning

Rating Sudoku puzzles strikes me as a very inexact science. I generally try to play the most difficult sounding level given - on the web that often means presumptuous names like "Super Evil, Infernal Brain Buster from Hell". In any case, from any given source I spend an hour on some puzzles with a rating like this, and five minutes on another. I will eventually implement a rating system that I hope will be more accurate than that, but for now I'm using the observation that "Easy" rated puzzles tend to be 30-something given tiles, and "Hard" rated puzzled tend to be 26 or so given tiles. Hence, a grading of levels between these extremes.