With one matchday to go, Arsenal are sitting on 12 points in Group F but are still not officialy through to the Round of 16. How can that be? Thanks to Marseille losing each of their first five games, Dortmund and Napoli are both sitting on nine points and are also very much in the running for a place in the knockout stage.
If Napoli beat Arsenal at home on the final day and Dortmund take care of Marseille as expected, all three teams would sit on 12 points. And thanks to UEFA’s peculiar tie-breaking rules, figuring out who would move on in that very possible scenario is not so simple.
In all three teams are tied on 12 points, the two with the best goal difference in matches involving only the three clubs in question move on to the Round of 16. The results against Marseille get thrown out. In those games, Arsenal lead with a +2 goal difference, while Dortmund are +1, and Napoli are -3.
Since Dortmund plays Marseille last, they will remain at +1 and, if all three clubs are on 12 points, will definitely advance. In that scenario, Arsenal would still move on if they lose by less than three goals.
Here are the scenarios each team would need to qualify:
Arsenal: A win or tie in Napoli will be enough to put them through, as would a Dortmund loss or draw. If Dortmund win, the Gunners can also advance if they lose to Napoli by less than three goals.
Dortmund: Very straightforward: a win and they’re in. A draw would be enough if Arsenal tie or beat Napoli. A loss to Marseille could still be enough if Arsenal beat Napoli.
Napoli: They face the toughest road. If Napoli win by three or more goals, they are guaranteed a spot in the next round. A win by anything less and they’ll need Marseille to get at least a point against Dortmund. If Napoli tie against the Gunners, Marseille would need to beat Dortmund.