They had the Europa this season and actually played better in the league when they had the midweek games (fun discussion on here about it, I was on the side that it's better to play every few days and shut everything out but the football, one of our lads, possibly Bernardo, said the same last night), next season will be tougher alright as Newcastle are on the up and Chelsea/dippers can't be as poor again, but as I said they've scope to improve and their points total this season will speak for itself.
In terms of figuring them out, easier said than done, they're not doing anything new or groundbreaking, they're just a very good side, even if they're not at our level yet.
They've gotten lucky at times this season, yes and there's some obvious areas in their squad that need strengthened (Holding is shite for starters and they need another centre back, Xhaka should be a squad player not a starter, White is useless in attack) but if they address that in the transfer window they'd be my favourites for top 4 of the other teams at the start of next season and while they might not sustain a title challenge it wouldn't be a surprise if they did.