Positive aspects of winning teams (7)
I believe the answer is:
upsides
'positive aspects' is the definition.
(I've seen this before)
'winning teams' is the wordplay.
'winning' becomes 'up' (I've seen this in other clues).
'teams' becomes 'sides' (I've seen this before).
'up'+'sides'='UPSIDES'
'of' acts as a link.
(Other definitions for upsides that I've seen before include "On a par (with); pie suds (anagram)" , "Positive attributes" , "positive features" , "Level" , "Positive aspects" .)