翻译：专家专家，专门最佳

The one who is the best in this field is the specialist.

A good expert is the one that being good in a specific field.
这种句子肯定要意译啊,无法像中文那样做到有韵律.

The best expert is expected to be of expertise.

An expert ---best at his major.

我还是比较同意这个
The best expert is expected to be of expertise.