And please also remember that on sector you might not always have the bigger picture. It may be that a stack swap is done from LAM-BIG creating Tiger holding as the GS's know that on that particular day LYD sector have more capacity than others. Tiger is often also favoured as it is closer in that some other outer holds and with well established procedures.
As a controller and a GS I would say that I try never to stack swap without good reason; that I ALWAYS ask the controller concerned if they can accept the swap (remembering that I'm not on radar at that time so may not have the full picture of the sector) and you can refuse if there is good reason to do so. HOwever, if you're bandboxed and say no then don't be surprised if I split it then ask again!
I don't do Airports/EAT's at the moment, but I too have noticed a difference when I'm on radar - however, I'm raising it internally too - I hope you folk are as well, as whinging on here won't get us anywhere!
And having been around a while I have seen one go LAM - BIG - OCK - BOV once!
Cheers,
N
"Keep smiling - it makes people wonder what you're up to..."