i was under the impression that it doesn't really matter about gaps with ranks - it's basically the ranks which make all the difference...
Utlimately you must be allocated an assessment mark out of 100. If gap does not matter than how do the board decide what assessment mark you are allocated?
When the board lady came to my school to explain that stuff she just glossed over it and said something like - the top student get the highest hsc mark, and the worst ranked student get the lowest hsc mark, and the marks in between are "averaged".
There was this powerpoint slide that I remeber vividly which has a tabulated example of the process. IT shows the rank one student taking the best mark, and the rank last student taking the worst mark, and the marks in between are in decimals (e.g. 87.5, 64.2, 45.6...etc.)
I take it that the fact there are decimal figures infers that your classmates' mark do have an effect on your own - and I presumed the effect is that if you have a crappy class and you failed to get rank 1, your assessment marks will be pulled down by the averaging process.
Meh, bunch of mumble jumbo, just study hard and ignore the crap above.