*To add to Lucian's answer:*  Try to short list proposals that actually speak to your need as articulated in your RFP or SOW.  If you asked for A (i.e. website or app), a proposal should at least explain how they will do A, before going on at length about their expertise in B (i.e. brand identity).

In my experience, there is no purely algorithmic approach in selecting creative proposals. It is a lot of vetting, short listing, reviewing work samples that match your aesthetic, and Q and A with creatives.