Your guess is as good as mine is a way of saying you have no idea either. Honestly, your guess is as good as mine.
It answers a question by refusing it, politely and without pretence of knowledge. It works as a whole sentence and is always said, never written in a report.
1phraseyour guess is as good as mineA way of saying: I have no idea either.
“When the work will finish, your guess is as good as mine.”
your guess is as good as mine is a phrase.
Practised in Idioms