rayter 1.0.2

Description:

rayter 1.0.2

Rayter
Rayter is a program for generating player ratings from a number of games,
with the results stored in a file.
It can be used in the form as a command line program, or as a Python library.
Installing Rayter
pip install rayter

Running Rayter Command Line Tool
rayter games_file.txt

Using Rayter as a library
Rayter can be used as a python library
>>> from rayter.rater import rate_single_game, SCORE_TYPE_HIGH_SCORE
>>> scores = [100, 74, 93]
>>> ratings = [1889, 1400, 1662]
>>> rating_changes = rate_single_game(scores, ratings, score_type=SCORE_TYPE_HIGH_SCORE)
>>> rating_changes
[-1.7346441947565552, -1.3906367041198422, 3.1252808988764116]

Rayter file format
The rayter file format expected by the Rayter Command Line Tool is designed
to be easily created by hand using a text editor. Here is an example for a
file containing two games of Hearts:
score_type lowscore

game 2011-12-24 22:00
Jessica 95
Hugo 77
Jonatan 89
Jakob 103

game 2011-12-24 23:19
Hugo 107
Jonatan 96
Peter 65
Jakob 70

score_type lowscore means that in this game the goal is to have as
low score as possible. The options for score_type are lowscore,
highscore (the default, if score_type is not specified), and
winner_takes_all (used for games with binary results, e.g. Chess).
Number of whitespace characters doesn't matter.
The format of the timestamp is year-month-day hour:minute, where hour
is from 0 to 23. The timestamp is currently not used more than as an
identifier of the game.
Rayter Algorithm
Every player starts with a rating of 1000. The sum of all ratings will
always be 1000 * the number of players in the league. So if one player
gets +60 rating in a game, and all other players lose rating, the sum
of their rating change will be -60.
If a player with a rating of 1200 is playing against an opponent with
a rating of 1000, the first player is expected to get 20% more points
than the second one. That means that if the first player scores 240
points in the game, and the second player scores 200, the rating
change of both players will be 0, since 240 divided by 200 equals 1200
divided by 1000.
Example:
Here are some results in a made-up card game:
game 2011-12-24 23:19
Dahlia 27
John 15
Ahmed 14
Lei 10

game 2011-12-25 21:12
John 23
Dahlia 10
Lei 4
Ahmed 4

After the first game, the ratings will look like this:
Name Games Rating Delta
Dahlia 1 1032 32
John 1 995 -5
Ahmed 1 992 -8
Lei 1 980 -20

When the second game was played, the ratings changed to this:
Name Games Rating Delta
John 2 1058 62
Dahlia 2 1029 -3
Ahmed 2 962 -30
Lei 2 951 -30

For the full details see the rate_single_game() function in rater.py.