bet on the wrong horse可不是赌错了马，而是估计错误；希望落空了；看走眼了。

【例句】
He rarely backs the wrong horse when it comes to investing in stocks.
他在炒股票时很少看走眼。

He expected Stevenson to be elected President in 1952 but as it happened, he bet on the wrong horse.
他预料斯蒂文森会于1952年当选总统，可结果他完全估错了。