one man's guess is as good as anther's.

问题描述:

one man's guess is as good as anther's.

同意冰儿的解释.
不过,英语中还有一句:Your guess is as good as mine.我和你一样对此一无所知.
这句话如果要翻译,最好译成:凡是猜的,都是说不准的/靠不住的.