shot in the dark字面意思在黑暗中拍摄，引申为瞎猜；漫无目标地瞎猜。

【例句】
The figure he came up with was really just a shot in the dark.
他得出的数字实际上只是瞎猜而已。

We had nothing to go by. It was a shot in the dark, but it turned out right.
我们是没有根据的，只不过瞎猜，可是结果却猜对了。