The rating system

A rating is an approximate measure of a player's strength. A higher
rating means a better player. On ISC the average rating is around 900,
expert players are around 1800.

The formula used for calculating rating changes depends if you have
an established rating or a provisional one.A player is **provisional**
if he doesn't have 11 rated games. To check how many rated games you
have type on command finger.
Only the games played against established players are rated. After completing
your first game against an established player you will get a provisional
rating.

__provisional vs provisional__

If both players have a provisional rating the game will not
be rated, and it will not count in stats.

__provisional vs established__

The formula used for the provisional player is
based on the average rating of his opponents and the number of his own
wins and losses. This formula can produce strange results since you
can lose points after winning a game if your opponent’s rating is below
average.

For a provisional player the **BEST** column
in the finger info shows the average rating of the opponents.

If this average is **1231** and you won **4** games and lost **4**,
your rating will be **1231**. If you won **3**
games and lost **0**, your rating will be **1629**.

If you’re the established player, the rating
points that you would normaly win it will be divided by **(11 - n)**,
where **n** is one plus the number of games your opponent has played.

__established vs established__

The rating formula used when both
players have an established rating is based on the opponent’s rating
and the score difference. You can win or lose anywhere between **0**
and **40** points.

If your opponent has the same rating as you and you win with a score
difference of **1** point, you will get **11** rating points.
For a score difference of **200** points you will get **21** rating
points.

You can see how your rating will be affected
before the game starts. Click on the person’s name and select **Assess**.
Alternatively, you can type assess
name in the command mode.

The assess command will show the rating changes for every dictionary.

rating
- to see the formula used for calculating rating changes