Admissions banding in SIMS - ?!

[ButteryBee]

Hi we have been trying to use SIMS to work through applying our admissions criteria for Year 7 applications. We are using banding based on CAT scores, taking 20% of our students from each band. The problem is we have lots of students with CAT scores which fall on the edge of two bands, and SIMS seems to be quite arbitrary in which students go in which band - it doesn't appear to be baed on any of our other criteria or even alphabetical.

I'm wondering if we need to add distance as a filter in the banding but not sure?

Thanks in advance for your help!