**Colley**: A linear system that only uses wins and losses.

**Massey**: A linear system that incorporates the scores of games.

**Uniform Weighting**: Each game is weighted equally regardless of the day
it was played.

**Linear Weighted Time**:
Games are weighted based on the day they were played. The value of
games on each day are given by a line through values you choose for
the first day in the time period and the value of a game for the
minimum of today and June 10.

**Step Weighted Time**:
Games are weighted based on the day they were played. The time period
is divided into equal sized intervals, according to the days in the
period, with a game in each interval weighted the same. The weights
used in each interval are chosen by you.

**Log Weighted Time**:
Games are weighted based on the day they were played. The value of
games on each day are given by logarithmic curve defined by two values
you choose. Games played today (or on June 10) are weighted at 100%.
You choose the number of years ago for which a game should be weighted
at 50% of a game played today and the number of years ago for
which a game should be weighted at 95%. These numbers can be fractions
of years.
The number of years ago for which a game should be weighted at 95% of
a game played today. It can be a fraction of years.

**Weighting by Type of Game**:
Nations play different types of international games. Each type of game
has a different purpose and may be approached differently by teams.
Teams may take some games more seriously than others as games such as
Friendlies have no bearing on their qualification for the World Cup.
These weights allow you to control how much impact each type of game
should have on the rankings. These weights are multiplied by the
weighting by time to give the games final weight. In the Colley
method, for games won in Penalty Shootout, the weighting is also
multiplied by that parameter.

**Linear weighting parameters**:
The value of a game played on the first day of the time period.
The value of a game played today (or June 10).

**Stepweights**:
The weight used in each interval. The time period is divided into
equal intervals based on the number of intervals given.

**Value of Penalty Shootout Win**:
Colley: The weight of a game won in penalty shootout. Weight must be
between 0 and 0.5.
Massey: The value of a win by penalty shootout in goals. A value of 1
implies that a penalty shootout win is equivalent to winning the game
in regulation by 1 goal. The value must be between 0 and 1.