Advanced subjects typically scale according to their candidature's performance on exam questions common to their corresponding regular subjects.
So for example in 1st year Maths, usually the multiple choice section of the final exam is common between Regular and Advanced.
Generally, advanced do better than regular in that common section hence advanced scales better. However, there is also the possibility of the highly unlikely event of advanced people doing worse than regular people in the common questions in which case regular scales better...lol
Typically, the average for advanced units is a low-mid credit, whereas for regular, it's a mid-high pass. But that's only because the advanced students are usually people of higher academic ability in the subject area compared to regular students.
