Is there a difference between "bäst" and "bästa"?
and "först" vs "första", Im guessing it would be the same principle?

Because they don't seem to follow the usual adjective rules

Question

Is there a difference between "bäst" and "bästa"?
and "först" vs "första", Im guessing it would be the same principle?

Because they don't seem to follow the usual adjective rules

Answer

I know nothing about grammar rules for adjectives, but you may want to check out this page: https://sv.wiktionary.org/wiki/bra

The table on the right might help you out.

Cheers
Jörgen

Answer

Bäst is also an adverb. You cannot be "bästa", you can only be "bäst".

Jag är bäst - I am the best.
Jag är den bästa [noun]. - I am the best [noun].

Vilket land har bäst mat? - Which country has the best food?
Vilket land har den bästa maten? - Same