nobodyhome

04-10-2011, 01:54 AM

The new rating system has undergone some modifications from season 1. The base formula is still the same, but there are modifications on top of them. As a reminder, the base formula is:

New Rating = Old Rating + [ 50 * ( S - E ) ]

Where S is 1 if you won and 0 if you lost, and the value of E is calculated for each team as follows.

E = 1 / [1 + 10^ ([(Avg rating of your opponents)-(Avg rating of you and your teammates)] / 400)]

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However the change to your rating is now multiplied by a variable that we will call "uncertainty". This variable is influenced by two factors:

Inactivity/newness: If you have played less than 16 games in the past two weeks, the less games you have played, the higher the multiplier is. This is to allow new or rusty players to settle to their correct rating faster.

Streaking/trending: If in the past 16 games you have won more than you lost (or lost more than you won) then your multiplier will be higher. This is to settle people to correct ratings faster if they are somehow very incorrectly rated (either they are a new player to ladder and 1500 is too high or too low, or they somehow became drastically better or drastically worse, for example by starting to play a new plane).

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Secondly, your rating change is divided by a variable that is a composite of the uncertainties of everybody else in the game. The higher everybody else's uncertainty is, the greater the divisor is. In essence, what this does is to make a game "worth" less in terms of your possible loss or gain if there happens to be someone in the game that is incorrectly rated (in this case, whether you win or lose is more determined by which way these incorrectly rated people are rated, as opposed to your own ability).

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Finally, you are given a few extra bonus points for each game you win. This serves as an inflationary factor to ladder making ratings trend upward over time, so that new players start near the bottom of the ladder rather than near the middle as previously, which more accurately reflects reality.

New Rating = Old Rating + [ 50 * ( S - E ) ]

Where S is 1 if you won and 0 if you lost, and the value of E is calculated for each team as follows.

E = 1 / [1 + 10^ ([(Avg rating of your opponents)-(Avg rating of you and your teammates)] / 400)]

----------------------

However the change to your rating is now multiplied by a variable that we will call "uncertainty". This variable is influenced by two factors:

Inactivity/newness: If you have played less than 16 games in the past two weeks, the less games you have played, the higher the multiplier is. This is to allow new or rusty players to settle to their correct rating faster.

Streaking/trending: If in the past 16 games you have won more than you lost (or lost more than you won) then your multiplier will be higher. This is to settle people to correct ratings faster if they are somehow very incorrectly rated (either they are a new player to ladder and 1500 is too high or too low, or they somehow became drastically better or drastically worse, for example by starting to play a new plane).

----------------------

Secondly, your rating change is divided by a variable that is a composite of the uncertainties of everybody else in the game. The higher everybody else's uncertainty is, the greater the divisor is. In essence, what this does is to make a game "worth" less in terms of your possible loss or gain if there happens to be someone in the game that is incorrectly rated (in this case, whether you win or lose is more determined by which way these incorrectly rated people are rated, as opposed to your own ability).

----------------------

Finally, you are given a few extra bonus points for each game you win. This serves as an inflationary factor to ladder making ratings trend upward over time, so that new players start near the bottom of the ladder rather than near the middle as previously, which more accurately reflects reality.