With only five match-days left in the 2023-24 Portugal Primeira Liga campaign, the model-based projections still narrow the championship down to a two-horse sprint between Lisbon and the blue half of Porto. Data from the FiveThirtyEight-inspired SPI index gives defending champions Benfica a 46 % probability of retaining the trophy, while last year’s runners-up Porto sit at 41 %. The remaining 13 % is essentially a lottery ticket for Sporting CP, who remain mathematically alive thanks to a favourable head-to-head record against both giants.
Goal-line models built on expected goals (xG) and expected goals against (xGA) show why the gap is so thin. Benfica’s attack is the most ruthless in the league, generating 2.11 xG per 90 even after adjusting for opponent strength, but their pressing block has slipped from last year’s elite level, allowing 0.97 xGA. Porto, conversely, trade a fraction of attacking volume (1.89 xG) for a stingier defensive framework that concedes only 0.83 xGA. Over a 34-game season that 0.14 xGA difference is worth roughly four extra clean sheets—enough to flip the title if head-to-head clashes end in stalemates.
The schedule adds another layer of uncertainty. Benfica still have to travel to both Braga and Guimarães, two grounds where they dropped points in 2022-23. Porto’s nightmare stretch comes in late May with a Lisbon derby against Sporting sandwiched between home ties with mid-table spoilers. Simulations that weight travel distance, rest days and injury-list length shave 3 % off Porto’s title odds relative to raw ability, leaving the SPI gap virtually unchanged.
Dark-horse watch: SC Braga and an in-form Vitória de Guimarães. Neither will win the league—both sit outside the 3 % trophy probability zone—but they are perfectly positioned to play king-maker. Braga’s 2024 winter reinforcement, winger Álvaro Djaló, has added 0.28 xG+xA per 90 since February; that individual breakout plus Champions League squad depth makes them the most likely side to nick points from the big two. A single upset in Match-day 31 or 32 could shift the betting market as sharply as the underlying model.
Bottom-half variance is equally dramatic. Portimonense, Chaves and Estrela da Amadora are separated by just two points and share a combined 71 % relegation probability. Expected-points algorithms flag Estrela as the unluckiest outfit in the league—six goals below their xG tally—and therefore the most probable to escape the drop if finishing skill reverts to mean. Conversely, Chaves’ ageing defensive spine has conceded a league-worst 15 goals from set pieces; another two set-piece concessions in the run-in would push their survival odds below 25 %.
Key predictive indicators the model is watching:
1. Head-to-head goal differential: the first tie-breaker means Benfica’s +5 edge over Porto could be worth an extra half-point in expectation.
2. Squad rotation index: Champions League fatigue subtracted 0.09 points per match for Portuguese sides between 2018-23; with both giants still alive in Europe, bench depth will matter.
3. Injury delta: Benfica’s soft-tissue casualties have plateaued since hiring a new fitness coach in March, whereas Porto’s midfield engine room remains two injuries away from relying on untested U-21 players.
Bottom line: the title is still a coin-flip, but the edge is razor thin. If you forced the algorithm to pick today, the call is Benfica 46 %, Porto 41 %, chaos 13 %. In other words, block off the last two weekends of May—Portugal’s Primeira Liga is heading for photo-finish drama.
