I agree entirely with the theory, London Dude ^ Though I think I rather than D is more sensible/"likely". My suggestion has always been to convert A/I/T in to Z/U/P at 3 days before departure for Golds, if those buckets are still otherwise available for sale. Then at 2 days before if there's still seats left in those buckets, open them up to Silvers in addition. Then finally at 1 day before, let Blues get a look in too.