Michel
Mr. Chad Barker, I recently bought your Sudoku lessons. I was doing Sudoku close to 1 year, I read several courses that were free on the Internet, and I could not grasp when they explained, like you mentioned, x-wing, xyz-wing, Swordfish, etc, etc. After using your method after 1 or 2 days I realized I could complete diabolical Sudoku’s in about 30 to 35 minutes. Now I only works on diabolical Sudoku and have fun doing it. Best regards,