Your end of year marks you get on your report or whatever are used only to determine spacing and rankings. I don't know exactly, but I understand it as: When sent to the BOS, the allign them, i.e the top external mark from the exams becomes the maximum, or top internal mark. So if someone were to get 86% externally, the person who came first would get 86% internally. The rest of the marks are then curve fitted, taking into account spacing. Then these marks are moderated in the same way as the HSC, so if 80 was the cutoff for 90, 86% would correspond to 93 etc.