Sure, I&#x27;ll give it a shot, although I&#x27;m not amongst your downvoters.<p>There are two ways to build a system like this: one requires no training and uses a heuristic. That is, you come up with a formula that you think will rank candidates well, plug input variables into it, and sort candidates based on the score. Such a system cannot learn, it is fixed; it can only be improved by a human tweaking it. The fact that we have no way to measure our success is irrelevant.<p>The other way is to build a learning system, and a learning system needs to be trained. This means there <i>must</i> be either a set of training data (of positive examples with specified outcomes) or an objective goal function that can be computed on the output over which an optimization can be run.<p>Without these things (i.e., when the results are too subjective and we&#x27;re unable to assign a reliable score to the outcome), machine learning is impossible, and the algorithm can never be trained to perform better than a human.