How rare is an unconditional from Birmingham?

I presume that they are only giving unconditionals to students predicted above ABB+ with a safety margin. Otherwise their SNC planning probably goes haywire. If you have to accept a student with an unconditional, but they get BBB and have to count against your SNC, then you've shot yourself in the foot.

I don't know, but I suspect the ABB+ population at Birmingham varies greatly by course, but is only about 40-50% of their undergrad intake?

Many RG unis ask for AAA so if anything Birmingham is, in my eyes, trying to steal 'firms' from places like Nottingham or York, rather than trying to take 'firms' from UCL etc.