I see my description might have confused you.
20 points always for the winner will be added to what they had previously.
The one who loses will get points equal to the number of games they won in the sets they played in the match. So it is not a fixed number of points for the one who loses.
So a person who played 3 matches, won the first, lost the second(for example, may have won 3 games in 1st set, won the 2nd set with 6 games and lost 3rd set with 2 game win) and won the third, will get 20 + (3+6+2) + 20
After his second match he would need to have 20 + 11.
After his third match he would need to have 31 + 20 calculated.