2 part description of proof of storage http://metaquestions.me/2014/08/17/proof-of-storage-maidsafe-part-ii/ rank is simple in this case. Number of stored chunks - lost chunks. There are further measurements of results of many actions, not measuring single actions is important (i.e… b/w space cpu) I find measuring the results of combinations better and more secure as single actions have too many unknowns.
I do not buy into game theory though, I am not convinced at all its a natural state of a system in equilibrium. I feel Nash’s theories are incorrect and caused many problems in the world and still are, they sound very clever though Mind you so did spraying ddt at mosquitoes I think. We all need differing opinions though, helps us evolve. Many systems use single actions or weird measurements based on this type of thinking. Muhammad Yunus and the Grameen Bank showed game theory to be problematic via real world measurements of outcomes when banks and their game theory would not give loans etc.
In terms of knock on effects, I am not sure what that means. Perhaps if you can ask a bit more?