To expand on the above:

If you are all in the 4+ day bucket (ie you have 5 days of availability and the pilots junior to you also have 4 or more days) then you are all in the same 'days of availability grouping' and the junior guy should get the SC.

I think the international categories have even more 'days of availability groupings' but domestic is just 1, 2, 3 and 4+

You have to look at who else is in your grouping first, THEN it comes down to RAW buckets.