Originally Posted by punkalouver
If ATC is giving you an immediate descent due to traffic they are showing here that they have [probably] already made an error of some sort
Or they are handling a military aircraft with an emergency, or a military aircraft with whom they have lost communications and who is manoeuvring. [Added after punkalouver's edit: I don't think anyone has a good grasp of what probabilities may be involved here.]
You are right about it being an odds game. Profis call it a "decision problem under uncertainty". One of the main issues for me is that none of the experts who study and devise strategies for such "decision problems under uncertainty" would go so far as to make a strategy compulsory. But that is what the BFU recommended about TCAS RAs, and that is what other organisations are promoting.
PBL