If you want to know how complicated figuring the CR is, go here: https://docs.google.com/spreadsheets/d/16lbseYDvYq985rCw-RPKsSGPDGAlj7kkpmiQWYC88ro/edit#gid=0 And then, this is only a guideline.
This is the most comprehensive CR calculator there is. Sure, MPMB probably could program it, but...