How are the points in CSS specificity calculated

Question

Researching specificity I stumbled upon this blog - http://www.htmldog.com/guides/cssadvanced/specificity/

It states that specificity is a point-scoring system for

Answer 1

I don't believe that the blog's explanation is correct. The specification is here:

http://www.w3.org/TR/CSS2/cascade.html#specificity

"Points" from a class selector can't add up to be more important than an "id" selector. It just doesn't work like that.