back the wrong horse （挺错了马）

cherishie

back the wrong horse
If you back the wrong horse, you give your support to the losing side in something.
如果你力挺一批错误的马，你把你的支持给了失利的一方。
上面整个短语的意思就是下错了赌注。在提及赌马的时候尤为形象，因为这个词从17世纪晚期就开始用在赌马这个项目上了。但现在又很多延伸用法，比如用在选举、投资等不回报不确定的事情上。back是“后背”的意思，这里是动词，给你撑一撑腰，然你腰杆子直一点，就是我们经常说的：我挺你 (I’ll back you up).

Jones garnered only a few hundred votes; we obviously backed the wrong horse. (Jones仅仅收获了几百张选票，我们显然下错了注)
It was only after 白木鬼 had invested all the money that he discovered he'd been backing the wrong horse. (白木鬼刚把全部家当都投上去，就发现自己选错了股，下错了注)

伊人独酌

So, we should take a full consideration before we make the decision

Dean

Look/Think before you leap. 三思而后行！