Champion: 'Good to crack original thinker's crosswords' (6,6)
I believe the answer is:
knight errant
'crack original thinker's crosswords' is the definition.
The definition suggests a singular noun which matches the answer.
'champion good' is the wordplay.
'champion' becomes 'knight' (I have seen 'Heroic champion' mean 'knight' so perhaps 'champion' could also mean 'knight').
'good' becomes 'errant' (I can't explain this - if you can you should believe this answer much more).
'knight'+'errant'='KNIGHT-ERRANT'
'to' is the link.
Can you help me to learn more?
(Other definitions for knight errant that I've seen before include "Chivalrous wanderer" , "Chivalrous quester" , "Adventurer" .)