partypooper, by default is spot on actually. Nothing wrong with that at all. Some threads I reckon I've read up to 20 times, and some select posters I've read and re-read.

I think the reasons most systems fall over is lack of logic.
Far too many rules are another reason too, and the integrity of the data and the volume of the sample.

Chrome Prince has been banging on about getting the best possible price for long enough. That's logical ..... and fairly easy to do, but not everyone does it do they?