Talk:Champion Mastery/@comment-25122281-20150705191723/@comment-26152856-20150706104134

It's heavily favored towards winning. A victory usually gives more than 1200 CP, while a loss gives about 150 CP.

The grade does influence CP gains. However, it's mostly supposed to be a performance indication for yourself. Hence, you may strive to improve your gameplay and continously score A's or better with your favorite champion.