So far ahead, number in tug (2,2,3)
I believe the answer is:
up to now
'so far' is the definition.
(I've seen this before)
'ahead number in tug' is the wordplay.
'ahead' becomes 'up' (similar in meaning).
'number' becomes 'no' (abbreviation).
'in' means one lot of letters goes inside another.
'tug' becomes 'tow' (I've seen this before).
'no' placed inside 'tow' is 'tonow'.
'up'+'tonow'='UP TO NOW'
(Other definitions for up to now that I've seen before include "Hitherto" , "So far" .)