# Serie A Regression Watch: Pisa's 20-Point xPoints Deficit and Inter's Charmed Life
Pisa have generated enough quality this season to be sitting nearly 21 points higher in the table. They are not. That gap, an xPoints deficit of -20.79, is the largest in Serie A and one of the most extreme figures across Europe's top leagues this spring. Somewhere between the expected and the actual, a lot of finishing variance, goalkeeping heroics from the other side, and plain old bad timing have conspired against them. The question for anyone watching the market is not whether this is sustainable. It is how quickly it unwinds.
Due a Correction
Pisa are the poster child for this column. A Luck Index of -82 is staggering. Their net expected goal difference sits at -18.46, meaning the underlying quality of chances they've created versus those they've conceded paints a grim picture on its own, but even accounting for that, the actual points haul has been dramatically worse than the model expects. Teams carrying this kind of xPoints gap historically see a correction within five to eight matches. Bookmakers tend to anchor on recent results, which means Pisa's lines may still reflect the worst version of their season rather than the probabilistic middle ground.
Hellas Verona are running a nearly identical xPoints gap at -20.64, with a Luck Index of -56. Their net xG of -11.01 tells you Verona are not secretly a good team by the underlying numbers. They are, however, a team that has been meaningfully worse in the standings than even their modest expected output warrants. That distinction matters. Regression does not require quality. It requires variance returning to the mean. Verona's results have been unlucky relative to their own baseline, and baselines, even low ones, tend to reassert themselves.
Fiorentina present the most interesting case of the three. Their net xG is actually positive at 4.42, which means they've been creating more and better chances than they've allowed. Despite that, they sit 13.38 points below their expected total, carrying a Luck Index of -42. A positive-xG team running this far below expected points is typically one where finishing, set-piece variance, or individual errors have been the primary drag. Those are the exact categories where regression tends to arrive fastest.
Sometimes the model just points at a team and raises an eyebrow.
Living on Borrowed Luck
Inter lead the league in net xG at a dominant 35.08, so the underlying quality is undeniable. But they've still managed to outperform their expected points by 13.56, a Luck Index of 50. The practical read here is that Inter are genuinely elite and also genuinely fortunate. Markets pricing Inter as if their current points-per-game rate is their true talent level may be slightly generous. Even dominant teams regress when they've been converting close matches at unsustainable rates.
Napoli have banked 14.86 more points than the model expected, the largest raw xPoints surplus in the league. Their net xG of 11.70 is solid but does not support a team running nearly 15 points above expectation. A Luck Index of 28 suggests meaningful overperformance, the kind that tends to compress over a final stretch of fixtures.
AC Milan are 9.19 points above their expected total with a Luck Index of 27. Their net xG of 16.18 is strong, placing them clearly in the upper tier, but the gap between underlying performance and actual points suggests a handful of tight results have broken disproportionately their way.
The Regression Window
In league football, xPoints gaps of this magnitude typically close over a window of roughly five to ten matches. The mechanism is straightforward: finishing rates normalize, save percentages revert, and the variance embedded in one-goal results starts to even out. With Serie A's final stretch now in view, the runway is short but historically sufficient for meaningful correction in both directions. The data does not care about narratives. It just describes the gap between what happened and what probably should have.