David B Williams wrote:
Does this mean "best story that has been translated" or "best translation of a story"? Yet another area of ambiguity in our mongrel language. 
Probably a fusion. From a lousy story well-translated, a great story poorly translated, and a great story well-translated, I would presume the latter would win. Then again it may be like the Hugos, where often it's the most popular story that wins.