back the wrong horse
US /bæk ðə rɔŋ hɔrs/
UK /bæk ðə rɔŋ hɔrs/
1.
to support a person or thing that is not successful or that turns out to be a bad choice
:
•
I really backed the wrong horse when I invested all my savings in that failing company.
•
Many critics felt the director had backed the wrong horse with his experimental film.