Thanks Breanne. I've learned some things since I made the original post. I believe that the clues and grid always give enough information to solve the puzzle. However, I haven't quite figured some of them out yet. As to guessing, I choose a guess where there are only 2 possibilities. That way, you have a 50% chance of being right or wrong. Also, if you have a clue where one 50% shot yields 2 absolute answers, use that to maximize your options. Lastly, do you have any idea how long it takes to get good at these. I only began on November 8, 2009... I'd never done a logic puzzle before then.