Hi Doug
Thanks for an excellent and informative reply, which answers my question exactly and now I understand greening across the book ( I think

)
Watching some of the BA videos I was mistakenly thinking that BA was placing bets on the other runners in the field to green up across the card.
I think from your reply that from my example if I had layed an additional £0.66 at 3 to show a £16.66 profit regardles of the outcome on my single selection, then
BA would show this £16.66 across the field (ie £16.66 in each and every horses card for that race)<-- ıs this a correct assumption.
I currently use a quick calculator to equalise profits on a selection which I found here
http://www.chromaweb.com/bets/calculator/index.php
but once I start using BA I see the calculations are done for you automatically.
To clarify my position for others reading this I do not currently have the BA software and am in the research and paper trading stage of my trading career.
Reading through lots of posts here it is refreshing to see so many positive and helpful answers to newbie questions ( So many other forums have an attitude to belittle and intimidate newbies)
Thanks again Doug for your excellent reply
Jamie