Doing a typical amount of damage given a rag (9)
I believe the answer is:
averaging
'doing a typical amount' is the definition.
(doing an average amount)
'damage given a rag' is the wordplay.
'damage' indicates an anagram (I've seen this in other clues).
'given'+'a'+'rag'='givenarag'
'givenarag' anagrammed gives 'AVERAGING'.
'of' is the link.
(Other definitions for averaging that I've seen before include "mean to emerge from it" , "Assessing the general quality" , "evening out" , "that has mean results" , "Taking a mean" .)