Napoli is on fine form and have more experienced players than inter from my discreetion since they have previously been topping the post on their league table for a very long time now although sometimes,things change and it seems Roma is always a problem to defeat at the tail end.
Inter, Milan, and Juventus are commonly also the main clubs dominant in the league. And yeah, Inter and Milan have proven that they are still in very great condition with their standings on right now.
For Napoli itself, it seems little bit surprising when seeing the result of the last match with Spezia today. Spezia is a small club, moreover compared with Napoli, it is like faraway. however, Spezia could win from Napoli in that last match even only 1-0. I ma sure that Napoli really got a big surprise on this match, they might not believe in what happened that they lost.
This always becomes a mean reason where everything can really happen on the field of match.