For Brown, BAD = Ken loses by a gap of >3%, OK = loss under 3%, GOOD = A Ken win.
For Cameron BAD = Boris loses, OK = Boris wins by under 5%, Good = Boris wins by over 5%, VERY GOOD = Boris wins by over 10%.
Rubbish. If Ken wins it's a good result for Labour and bad result for the Tories. If Boris wins it's vice versa. In this race, margins don't matter.