Just finished reading HOH-1. I really liked this book and as a newbie to poker I got a lot out of it. That said, there is something in the book that is repeated often but not explained. Harrington often refers to the "Gap Concept" when playing. I think it has to do with your starting hand requirements going up when entering a raised pot, but I don't understand what the rule(s) actually is. Can someone explain the Gap Concept, please?
Thanks,
Mark