Marking it as untriaged to get more inputs from dev team as it is feature request.

Thanks for the request tychogrouwstra@.

@Others, how possible is this?

It's possible: https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/css/CSSSelector.cpp?sq=package:chromium&dr=CSs&rcl=1471618369&l=95

But I'm not really convinced this would help. The ordering we do in SSP already indicates what styles override, which is a higher quality signal than just specificity on its own.

But maybe there's a usecase I'm not thinking of where specificity would communicate something that would help when the rule sorting doesn't.

I'll agree that the ordering is pretty intuitive, which makes it great.
When intending to override existing rules though, I'd imagined that info on
specificity values might make this intuition a bit more concrete.
The way I'd been thinking about this was when the user would like to add a
style rule so as to override existing competing rules. This inherently
involves a trade-off: you'd want to ensure the overriding style would have
a higher specificity, while preferably not making it so specific as to
become fragile in case of future changes, so preferably not much more
specific than necessary.
I wouldn't want to suggest cluttering the UI though; hence the idea of
putting it in a tooltip perhaps.

The specificity by itself wouldn't help much: users would need to know how to change it. This would require understanding of specificity calculatation.

Closing this for now.