Rivaling mechanics - any actual hard data?

[Chaingun]

EDIT: Duh I'm tired, I first answered a different question

I might look it up tomorrow. It builds some sort of rival list, which also passes through a validity check, at least that check I could explain.

 

[Chaingun]

(For anyone reading afterwards: I answered how the AI behaves when it picks rivals, and yeah, randomness was one of several factors.)

Generally, in AI we stay away from complete randomness or complete predictability and just mix in a limited amount of it to make decisions somewhat less easy to predict.