The best I can find before the season started is 6 from 8. This one also got 6. and this one.. Heaps got 5 though.
That probably would fit if you did some study on the top 8. I'd say the number of "wildcard" teams that usually sneak into the 8 is about 3, regardless of the position finished in, while there are always 5 legit threats to the premiership. Of course the 5th team would get comfortably overshadowed by the top 4 in terms of premiership success.
