I've actually been thinking about this a bunch. What I'd love to find out is how often dry flops happen vs wet flops and how much doing something like giving up to aggression on dry flops could cost you.

Here are the dimentions I would use to try to build a mathematical model:

High Cardness: How many cards on the flop are in the range people are likely to play in big card hands A-T. In short-handed situations 9 and 8 have value here too.

Connectedness: How many likely holdings would have flopped a straight or have a straight draw.

Suitedness: Monotone, two-tone or Rainbow.

On top of this, a pair on the flop is pretty dry depending on how big the pair is. 3ok is pretty much the driest flop possible.