As the fight for London between Ken and Boris, and the other chap, reaches its final round, with opinion polls telling us how we will vote, it’s timely to reflect on what will, really, be influencing our decision.

Will Ken get my vote because I admire much of what he has done to make London a better place to live in and that he is clearly a consumate politician when it comes to getting more out of the public purse for London? Or because I met him once , on the underground, where he kindly gave me directions to the right platform?

Will Boris get it because some of his ideas make sense despite his lack of practical experience, or because he gets rid of bendy busses or because he will do more for grass root sport, something I feel strongly about? Or because I warm to his off-the wall sense of humour?

The truth, of course, is that, whilst I like to think my rational self will weigh up the arguments and inform the decision, my instinctive feelings for them as people will play their part. It’s a question of chemistry.

Over the last few years ‘chemistry meetings’ have become an increasingly accepted part of the pitch process. Seemingly an innocuous get together ,with no set agenda, these meetings can be more critical to the decision than a final presentation. They should ,therefore, be given the same level of energy and preparation.

Some ideas on how to do this, Chemistry Lessons, are under Best Practice Guides.