In my opinion, Annabeth has more knowledge than any other character, which makes her a genius but not the smartest or the better strategist. Percy has her beat in both, and being the god of improvisation that he is just puts him in a league of his own. Leo has her beat in so many things, too. Practical knowledge, mechanics, calculations, innovative abilities, and so on.
I don't care if this is a hot take or not, but Annabeth Chase is not that much smarter than Percy Jackson, if she is at all.
Yes, she is a genius, yes, canonically she is the most brilliant living child of Athena, yes, she certainly has fullfilled some incredible feats and yes, she is, without a doubt, one of the smartest characters in any of Rick's works.
But never in those books , neither in the og series, nor in heroes of Olympus, has Annabeth done anything, that proves she is smarter than Percy to any considerable degree. At the most, it is told to us through inner thoughts or dialogue, but it is never really shown trough any actions.
I often get the feeling that her intelligence often gets overestimated in the fandom, or, at least, that the intelligence of the characters around her gets underestimated to elevate Annabeth.
Because, even if she were the smartest of the seven (which is very much debatable), it would be a very close call. Especially compared to characters like Leo or Percy, who rival or sometimes even surpass her in that regard (Leo with building the Argo II or his general mathematic genius, and Percy with his battle IQ or manipulative abilities)
Annabeth Chase is a genius and like I said, one of the smartest characters in the riordan verse, but so is Percy Jackson (and Leo Valdez)