Regression

Taking inspiration from Sheffield United, I'm going to outline some clubs that are either overachieving or underachieving this season that I have good reason to believe will drastically move up or down respectively next season. First, however, I want to caveat a couple things. I'm using understat data, which relies on the expected points model, which is based on what "should" happen looking at chances, meaning the context isn't there. The other thing is I'm forecasting what each of these teams will be like, as well as the way football is played in said league and what other teams will do.

PL: up- Brighton, Fulham*, Chelsea

down- United, Leicester, Everton, Palace

La Liga:

up- Eibar*, Huesca*, Celta, Villarreal

down- Atleti, Madrid, Sevilla, Granada

Serie A:

up- Parma*, Udinese, Torino*

down- Lazio, Milan, Inter

Bundesliga:

up- Hertha*, Dortmund, Mainz*

down- Bayern, Wolfsburg

* = relegation possible/likely

Some of these clubs I've listed are likely doing worse/better than they "should" be due to killer finishing or guys that can't hit the proverbial barn door. Others are there due to style. For instance, one thing xG is worthless at, at least the models that don't take defenders and other nuanced context into account, is game state and the actual quality of the chance. Like I always say, a shot against a set defense in a low block is completely different from a 2v1, and a defender swinging his weak foot from a set-piece chance is a much lower likelihood opportunity than a "world class" finisher with no defenders around.

For now I'll do one from each category in each of the listed leagues.

Hertha/Mainz and Wolfsburg- this one is obviously contingent on relegation, and technically both can stay up if Bielefeld or Bremen join Schalke in the second tier directly. At some point Hertha will more or less have to find a solution that sticks. They have too much money and too many half decent players to be battling relegation. Mainz, on the other hand, are pretty bad, but the entire season they've been on the wrong side of luck. Wolfsburg IMO will only go down, especially if Glasner leaves. They lost out to AEK Athens in the Europa League qualifiers, and that almost certainly contributed to the success they've had this season. Playing in Europe for certain at this point will test the squad, and that tends to cost teams that aren't well stocked squad wise. Dortmund will be interesting to observe, knowing they may not have CL money which will likely mean stars will be sold. I don't like Rose as the fit, so we'll see how that turns out.

Torino and both Milan clubs- I know I said it would only be one per league, but I have a caveat for Inter. If they try in the Champions League, they'll fall off for sure. Whether it's enough to lose their hold on the title, or even miss out on top four, is anybody's guess. It also depends on the financial situation higher up. Milan, on the other hand, are currently in freefall. Ibra re-signed, which is a questionable decision, and it's entirely possible that they'll end up in the Europa League again, which would be devastating. Torino is in the same boat as Hertha. Should be mid-table at worst, but here we are. I always comment that Belotti should leave, and he should, but if he stays and they add a couple pieces they'll certainly rise in the standings.

Villarreal and Granada- so, this one was tough. Both in Europa this season, potentially next as well, but the underlying numbers tell a vastly different story. Villarreal, thanks to the Emery style of play, create loads of chances, whether high quality ones or not, and Granada simply do not. Timely goals are necessary, obviously, and that's why I reckon these two are so close in the table. The other two I could mention for worse results next season are Atleti and Sevilla, for different reasons. If Atleti keep this squad, they won't challenge. Sevilla are prone to selling, and if they lose Kounde or En-Nesyri and don't properly replace, and ignore the holes already in the squad, they'll be 4th at best.

Chelsea and Palace- honestly, there are good cases for all the clubs other than probably Fulham, unless they miraculously stay up and invest properly. I chose these two because it's too obvious. Tuchel has them one game from the CL final having come in halfway through the season, and they'll only strengthen. Meanwhile, Hodgson no longer can even say he's got a good defense, and the squad is aging rapidly. I always say one day they'll go down, Palace, but it probably won't happen next season given how crap the bottom few teams are. Brighton, if they were to improve a number of positions, as well as keep Graham Potter, would be a good bet to elevate, maybe even top half, but that's unlikely to all come together.