In my experience at least 1 1/10 a week ***** up. I use them regualrly to beef up accumulators, and they can go wrong sometimes.
If you see a 1/10 but don't have at least a basic knowledge of the sport or the competitors, ie recent form, playing conditions etc, my advice would be not to place the bet. Handball, volleyball, etc etc look nice when you see that one side is massive favourite to win, but how can a UK based betting site have an intimate knowledge of a largely amateur european sport?
I shall take part though, nice thread.