Be aware of the facts as to how many runs have been made? (4,3,5)
I believe the answer is:
know the score
'to how many runs have been made?' is the definition.
I can't tell whether this defines the answer.
'be aware of the facts' is the wordplay.
'be aware of' becomes 'know' (I've seen this in another clue).
'the facts' becomes 'thescore' (I can't explain this - if you can you should give a lot more credence to this answer).
'know'+'thescore'='KNOW THE SCORE'
'as' is the link.
Can you help me to learn more?
(Other definitions for know the score that I've seen before include "Possess all the important facts" , "Be informed" , "be aware of the essential facts..." , "Orchestra should" , "as should an orchestral musician?" .)