Warrior's Block Value Bug

Hi everyone.

I was perusing through the forums some more and was trying to read up on the block value bug for warriors. I don't quite understand what it is talking about (is it just diminishing returns?), so if someone could help clarify that for me that would be great (was interested in playing prot PvP and not sure if it viable after trying to read about the bug).

I also noticed that someone had mentioned that the bug didn't exist on the Blackrock server. Is this bug here on Lord?

Thanks in advance.