back the wrong horse
US /bæk ðə rɔŋ hɔrs/
UK /bæk ðə rɔŋ hɔrs/

1.
apostar no cavalo errado, fazer a escolha errada
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.
Eu realmente apostei no cavalo errado quando investi todas as minhas economias naquela empresa falida.
•
Many critics felt the director had backed the wrong horse with his experimental film.
Muitos críticos sentiram que o diretor havia apostado no cavalo errado com seu filme experimental.