England's draw with Scotland showed just how confusing the European Championship format can be for the teams and even the organizers.
UEFA's official website stated ahead of Friday's game that a draw would secure England a spot in the round of 16 with a game to spare.
Once England had underwhelmingly clinched that point after being held to a 0-0 draw by Scotland, qualification seemed likely but not guaranteed.
England coach Gareth Southgate certainly wasn't celebrating advancing, and his team analysts were left crunching the data.
By Saturday morning, UEFA had determined that England had yet to be sure of at least going through among the four best third-place teams from the six groups.
As it stands, England is in second place in Group D behind the Czech Republic on goal difference. The two teams will play each other on Tuesday at Wembley Stadium. Scotland and Croatia have one point each and will meet in Glasgow at the same time.
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Four points was enough for third-place teams to advance at Euro 2016 when the tournament first expanded from 16 to 24 teams. Even three points was enough for Northern Ireland and eventual champion Portugal to move into the knockout phase, but not enough for Albania and Turkey.
Teams level on points are separated first by their head-to-head record and then by goal difference, followed by goals scored.
Teams can end up hanging around waiting to discover if they make it. Albania had to wait three days in 2016 before finally being eliminated.
The English are less likely to experience that fate and a victory over the Czech Republic will ensure first place in the group, with no calculations or tiebreakers needed. Then the last-16 match at Wembley would be against the second-place team in Group F, which could be France, Germany or Portugal.
So finishing second could be more appealing for England, since the opponent would be the Group E runner-up, which is currently Slovakia. But the game would be in Copenhagen rather than on home soil in England.
If the third-place team in Group D advances, the opposition would be a group winner.