Some of my co-workers are European soccer fans, so today at lunch we watched the Chelsea-Barcelona Champions League game.

In the knock-out stage, teams play 2 games against their opponents-- one game at home, and one on the road.

Here's the tiebreaker system:
1) The team that has the most combined goals in both games advances.
2) If they're tied, then the team who scored the most goals in their road game advances.
3) If both teams win once with the exact same score in each game, then they go to overtime and penalty kicks in the second game.

Barcelona won the first game at home 2-1.

Here's a summary of the tiebreaker scenario at 2 different points during the game:

Chelsea 1, Barcelona 0.
Aggregate goals: Chelsea 2, Barcelona 2.
Road goals: Chelsea 1, Barcelona 0.
Chelsea would advance to the next round.

Chelsea 3, Barcelona 2.
Aggregate goals: Chelsea 4, Barcelona 4.
Road goals: Barcelona 2, Chelsea 1.
Barcelona would advance to the next round.

Chelsea ended up winning the game 4-2. Their final goal was meaningless to the outcome of the individual game, but was necessary for them to advance to the next round.

How strange. They should do what hockey does... have each playoff game continue on until someone scores a sudden-death goal in overtime.