Hi, newbie here. The San Francisco Chronicle just started running Sudoku puzzles on Monday July 18. I never heard of sudoku before but now I think I'm addicted. (I am a longtime Dell logic puzzle fan) The Chronicle has 3 difficulty levels: white belt (easiest), brown belt, and black belt. They have not run a black belt puzzle yet, I am hoping for one tomorrow (Friday). The brown belt today took me about 30 minutes (no mistakes) but it's only the 4th sudoku I have done and so hopefully I will get faster with more experience. I am wondering how these 3 difficulty levels compare with the levels of pappacom puzzles and The Times levels (fiendish, etc). Have any of you sudoku veterans seen the S.F. Chronicle puzzles? Ideally I would like a difficulty level that takes me 45-50 minutes to solve because that is the length of my train ride to work. I'm expecting they might only run the black belt level on Fridays and Saturdays though.