The Chess Tournaments forum is weird in a way.
I will explain.
The forum only has over 1600 topics right now. Other forums have over 2000.
But even though it only has 1600 topics, it has over 22,300 posts!
That averages to 13.85 posts per topic.
I just wanted to point that out. 
The highly controversial USCF Issues forum contains 113,000 posts on 3700 topics, dwarfing all of the other Forums combined. However, only USCF adult members can log in.
Michael Aigner
This is the most useful forum IMHO.
You are right!
There are over 3700 topics in USCF Issues.
It has 113200 posts. That amounts to 30 posts per topic.