Four groups have teams locked on the same points, the same amount of goals scored AND identical goal difference as the race for the Round of 16 goes down to the wire.
Group B, Group F, Group G and Group H all have two teams neck-and-neck to reach the Round of 16, with little-known FIFA World Cup™ tie-breaker rules currently determining who finishes first and second or second and third in the group.
Spain and Portugal are currently separated by a 92nd minute yellow card, England and Belgium are currently separated by an 88th minute yellow card and Germany and Sweden are separated by a 95th minute goal.
There is also a possibility that the Socceroos and Denmark could be separated by one of the seven tie breakers should certain results be achieved in the final Group C matches.
According to the FIFA rule book, here are how groups will be separated should two teams be equal on points after all three games:
- Goal difference from all group matches
- Goals scored in all group matches
- Head-to-head in the group match between equal teams
- Goal difference in the group match between equal teams
- Number of goals scored in the group match between equal teams
- Fair Play standings (yellow card = -1, second yellow card = -3, straight red = -4)
- Team drawn out of a hat
Here are the equations of FIVE FIFA World Cup™ groups where the tie-breaker rules are currently in place, including an explainer about Australia's Group C equation.
1. Spain: 4 points, +1 goal difference, 4 goals scored
2. Portugal: 4 points, +1 goal difference, 4 goals scored
Spain and Portugal are currently equal on points, equal on goal difference AND have scored the same amount of goals.
The two teams played out a 3-3 draw in their Group B opener, which means they are also equal on head-to-head.
This means Spain are ahead of Portugal on Fair Play standings, with Spain receiving one yellow card in two games and Portugal receiving two yellow cards in two games.
Portugal's second yellow card came in the 92nd minute of their 1-0 win over Morocco, with Adrien Silva booked for time wasting.
2. Denmark: 4 points, +1 goal difference, 2 goals scored
3. Australia: 1 point, -1 goal difference, 2 goals scored
Australia's Group C could come down to potential tie-breaker rules should the Socceroos beat Peru and Denmark lose to France in the final game.
This would leave both teams on four points, with goal difference and goals scored the two next tie-breakers.
Should the Socceroos win 1-0 and Denmark lose 2-1, both teams would be level on points, goal difference (0), goals scored (3) and equal on head-to-head having played out a 1-1 draw.
This would leave Fair Play as the decider, with the Socceroos currently on three yellow cards, while Denmark have received four.
2. Germany: 3 points, 0 goal difference, 2 goals scored
3. Sweden: 3 point, 0 goal difference, 2 goals scored
Group F is also currently being decided by tie-breaker rules. With Mexico currently topping the standings on six points, Germany are edging Sweden.
But not on points, goal difference or goals scored, with sees Germany and Sweden deadlocked. Instead, the difference is Toni Kroos' 95th minute goal in the game between the two sides. This means Germany has the upper hand on head-to-head, having beaten Sweden 2-1.
1. England: 6 points, +6 goal difference, 8 goals scored
2. Belgium: 6 points, +6 goal difference, 8 goals scored
England and Belgium will both progress through Group G, having picked up six points from their opening two games against Panama and Tunisia.
Having both scored the same and conceded the same as each other, England and Belgium are currently separated by yellow cards.
Kevin De Bruyne's 88th minute yellow card for a high boot took Belgium to three bookings for the tournament so far, ahead of England's two.
The two teams play each other in the final group game to determine who tops the group.
1. Japan: 4 points, +1 goal difference, 4 goals scored
2. Senegal: 4 points, +1 goal difference, 4 goals scored
Japan and Senegal are equal on points, goal difference, goals scored and head-to-head, having drawn 2-2 on Monday morning AEST.
Senegal's Fair Play standing sees them trail Japan, having received five bookings to Japan's three.