New ask Hacker News story: Ask HN: Given two repos of code, what criteria would you use to grade quality?

Ask HN: Given two repos of code, what criteria would you use to grade quality?
2 by devrob | 5 comments on Hacker News.
I'm curious, given two repos containing code that accomplish the same goal and produce the same correct results per requirements, what quantitive and qualitative criteria would you use to grade reach repo and the engineer's skills that produced them? For e.g. some folks say "readability" and "understandability", but how do you define that and how do you think that would translate to a quantitative metric (if possible)?