Oxford pooling system

[PeterTavy]

Can anyone please explain the Oxford pooling/ two college system to me?
DD has very belatedly (and somewhat optimistically, as she good but below- average-for Oxbridge GCSEs) decided to put Oxford down as one of her Uni choices.
I understand the Cambridge pooling system because they make it very clear how they operate but can anyone explain the Oxford system to me?
She currently has no college preference because she's not familiar with any of them really but doesn't want to make an open application.
She looked at the college league tables and the ones she liked in the prospectus came out as last and middling. If she puts one of these down, is it less likely a second college will consider her?
If she chooses a large popular college e.g. Christ Church, is it more likely a second college will look at her?
Her school does send a few to Oxford each year but doesn't seem to share any info about previous offers/ colleges/ characteristics etc. and doesn't have an Oxbridge group/ special preparation, which is fine, but it's hard to get any information beyond the prospectus.

There isn't an 'Oxford system', every subject organizes admissions and pooling slightly differently. But the aim in each case is to ensure that the best candidates get accepted to some Oxford college, irrespective of where they applied to - i.e., as far as possible the college you applied to does not make a difference to your chance of getting in to Oxford.
The way it works in my subject, candidates are transferred from over subscribed colleges to (relatively) under subscribed colleges before interview, and again after the first interview. There is no sense in which you 'won't be considered' by certain colleges because of your choices, except that if a college has far more applicants than others, it won't be given more to consider before first interviews. My college would generally be considered a 'top' college on various criteria, but we have regularly taken candidates from other colleges on second interview.

In the past I think it was true that you could change your chances of getting in by applying to less popular colleges. I don't think that's really true any more so just put down your first choice and don't over think it.

She's absolutely fine Molio. And TBH very lucky to get I. Anywhere really. The other place could have said no too. I suspect most of the angst over Oxford was to do with the fact that her boyfriend is going there!

That's good Decorhate. A number of the DCs' friends have gone where she is and every single one loved it. I can see the bf thing is painful, especially if they've been together a while: the merits or otherwise of pre-existing relationships - a whole new thread :)

It has to be Wadham.

I think they only look at your best 8 GCSEs anyway.

That's not correct Brioche, not for Oxford and not for a number of unis. There are all sorts of calculations based on a number of factors which vary across the different unis and even within unis.