Attention to detail of former head about individual performance (9)
I believe the answer is:
exactness
'attention to detail' is the definition.
(thesaurus)
'former head about individual performance' is the wordplay.
'former' becomes 'ex'.
'head' becomes 'ness' (ness is a headland).
'about' means one lot of letters go next to another.
'individual performance' becomes 'act' (act is a kind of performance. I am not sure about the 'individual' bit.**).
'ness' after 'act' is 'actness'.
'ex'+'actness'='EXACTNESS'
'of' is the link.
Can you help me to learn more?
(Other definitions for exactness that I've seen before include "Precision" , "nice" , "truth?" .)