Atalanta do find it very difficult to win Inter, the last time that they met, Inter won the match. I believe that the same result will be replicated again. Inter knows how important this match is to them, they need all three points for them to maintain the first position. Napoli on the other hand, is playing with an average club, victory is sure for them.
Both teams have clear goals, we know this match is important for them, I know Inter is under pressure because if they lose or draw automatically Napoli can replace their place. Inter has a higher chance to win but seeing Atalanta with their performance lately and also they are playing at home they also have a chance to win. Betting on one of them will be risky so the comfortable choice is BTTS or over, I am sure this match will produce many goals.