Scotland and Denmark are both on 10 points.
The Danes have a handsome goal difference advantage of six goals, and that is the first deciding factor if teams are level on points – not head-to-head.
However, Scotland will be hoping they can get the job done without the need for such messiness.
We can probably assume Denmark will beat point-less Belarus at home in November – having thrashed them 6-0 last week – which would move them to 13 points.
If Scotland beat an already-out Greece in Athens, they would match that tally, setting up an high-anxiety decider at Hampden.
A draw in that one on 18 November would almost certainly favour the Danes, given the goal difference disparity.
Should the Scots draw in Athens, victory over Denmark would still be enough to win the group.
However, defeat for Scotland in Greece, coupled with a Denmark win over Belarus, would mean an extraordinary victory is required in that final game to give Clarke’s side any chance of automatic qualification.