If you need an example, you can use this one or make your own one, it doesn't matter.
A hurricane hit the Atlantic coast. Florida fared (the) worst with estimated damages of more than $50 billion.
There's no point in an article there. None! Articles are linked to a noun (apart from cases like 'the rich', 'the poor', etc. where it makes collective nouns). Is there a noun? None! And yet, there are more search results in Google News for the second option (though still only several thousand). What I want to figure out is which option complies with the grammar rules: putting the article between 'fare' and 'worst' or not doing so? Please give a satisfactory and convincing explanation if it's the former option (I see no point in using 'the', really). As I understand it, 'worst' here modifies the verb 'fare'. The part of speech that modifies verbs is the adverb. Whether superlative adverbs take 'the' or not is unclear for me. On the one hand, in the Longman dictionary, I see this. Note that it's not classified as an idiom.
You know him best – you should ask him.
On the other hand, on the ef.com I see this:
Everyone in the race ran fast, but John ran the fastest of all.
He played the best of any player.
Now, the question is, why the ef is it so? Is it because of 'of all' and 'of any player' respectively? But in the Longman example, 'of all' is also implied.