I am a Software Development Engineer in Test working for the Windows Sound team. You can contact me via email: mateer at microsoft dot com
Friend key: 28904932216450_59cd9d55374be03d8167d37c8ff4196b
With World Cup Group G standings being the way they are, I decided to read up on tiebreaks.
Here are the FIFA rules (PDF)
The relevant sections are:
18.4.a: ... with three points for a win, one point for a draw and no points for a defeat (league format)
18.6: In the league format, the ranking in each group is determined as follows:
a) greatest number of points obtained in all group matches; b) goal difference in all group matches; c) greatest number of goals scored in all group matches.
If two or more teams are equal on the basis of the above three criteria, their rankings shall be determined as follows:
d) greatest number of points obtained in the group matches between the teams concerned; e) goal difference resulting from the group matches between the teams concerned; f) greater number of goals scored in all group matches between the teams concerned; g) the goals scored away from home count double between the teams concerned (if the tie is only between two teams).
18.7 discusses play-off matches between teams that are still tied after all of 18.6.a-g are applied. As we'll see, there is no possibility of the United States being involved in a play-off.
Let's start with 18.6.a. The current point standings in Group G are:
The remaining games are United States-Germany and Portugal-Ghana.
If the United States-Germany game results in a tie, then the United States and Germany will have five points apiece, with a win and two ties. They will be the top two teams in the group, regardless of the outcome of the Portugal-Ghana game.
If the Portugal-Ghana game results in a tie, then Ghana and Portugal will have two points apiece, with two ties and a defeat. Regardless of the results of the United States-Germany game, the United States and Germany will be the top two teams in the group.
So we need only consider what happens if both games are decisive.
The winner of the United States-Germany game will have seven points, with two wins and a tie. They are in on points.
The loser of the Portugal-Ghana game will have one point, with one tie and two defeats. They are out on points.
The remaining two teams (the loser of the United States-Germany game, and the winner of the Portugal-Ghana game) will have four points apiece, with a win, a tie, and a defeat.
So in this scenario, 18.6.b will be invoked. At this point we have to look at the goal difference for the teams. (The goal difference for, say, Germany is just the number of goals Germany scored, minus the number of goals Germany allowed.) These are currently:
The raw numbers look good for Germany and the United States, and bad for Ghana and Portugal. But let's bear in mind that we are considering the scenario where Germany or the United States has just lost, and Ghana or Portugal has just won. How do you win? By scoring more goals than you allow! So the goal differential of the loser of the United States-Germany game will be lower than it is now, and the goal differential of the winner of the Portugal-Ghana game will be higher than it is now.
So as a United States fan:
What if Germany beats us, and Portugal beats Ghana, but the margin of victory of both games adds up to exactly four? Or what if Germany beats us and Ghana beats Portugal, and the margin of victory of both games adds up to precisely two - that is, each game is decided by a single goal?
We can still get in on 18.6.c. At this point we have to look at the number of goals scored by each team. These are currently:
Note that the United States has one more goal than Ghana, and two more goals than Portugal. This is good. In the "goal differential" case, there was a strong relationship between winning and changing your goal differential. But there is only a weak relationship between winning and changing your raw goal count.
For example, if Germany beats the United States 3-2, and Ghana beats Portugal 1-0, the United States will actually have pulled even farther ahead in the 18.6.c race!
What if Germany beats us, and Portugal beats Ghana, and the margin of victory of the two games adds up to exactly four, and Portugal's winning score is precisely two goals more than our losing score? Or what if Germany beats us and Ghana beats Portugal, and the margin of victory of both games adds up to precisely two, and Ghana's winning score is precisely one goal higher than our losing score?
Then we are in or out on 18.6.d-g. At this point we have to look at the results of the Ghana-United States and United States-Portugal matches. In each match, the first team is the home team and the second team is the away team.
Note there is no possibility of a playoff. Had the United States-Portugal game been a 0-0 tie instead of a 2-2 tie, that would have been a possibility, since double 0 is still 0.