Taking a chance, opens new clubs (2,4)
I believe the answer is:
on spec
'taking a chance' is the definition.
(as in building something on spec)
'opens new clubs' is the wordplay.
'new' is an anagram indicator.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'opens' is an anagram of 'onspe'.
'onspe'+'c'='ON SPEC'
(Other definitions for on spec that I've seen before include "gambling" , "experimentally" , "Taking a gamble" , "The sort of hopeful punt" .)