as likely as not
US /æz ˈlaɪkli æz nɑːt/
UK /æz ˈlaɪkli æz nɑːt/

1.
lo más probable es que, con toda probabilidad
very probable; almost certain
:
•
As likely as not, he'll be late again.
Lo más probable es que, llegue tarde de nuevo.
•
She'll as likely as not forget about the meeting.
Ella lo más probable es que olvide la reunión.