Elo Self-Play Update

Problem

Update player A's Elo rating after a self-play game.

E = 1 / (1 + 10 ** ((rating_b - rating_a) / 400)), and the new rating is rating_a + k * (score - E), where score is 1.0 for a win, 0.5 for a draw, and 0.0 for a loss.

Hint

Beating a stronger opponent moves the rating more than beating a weaker one.

Test cases

case 1

in: [1500,1500,1,32]

expected: 1516

case 2

in: [1500,1500,0.5,32]

expected: 1500

case 3

in: [1600,1400,0,20]

expected: 1584.8050614670408

case 4

in: [1400,1600,1,20]

expected: 1415.1949385329592

Starter codePython

def elo_self_play_update(rating_a, rating_b, score, k):
    # Your code here
    pass

4 test cases · run your code against them in the editor