Can somebody explain it to me that how in the Kentucky fried chicken-wings does this system counts Rank Rating? Whenever I hardtry, give in my everything to the game, and help my team to victory (usually 2nd or 3rd best in team according to K/DA, but that is irrelevant given the fact that I usually play Sentinel and giving intel to my team) gives me +21 points fair and square, but when in the very next game I get 3 AFK players (one of them joined in and out many rounds) and cannot surrender right away, the system deducts -20 points. No wonder we lost 0-13 that match, we were heavily outnumbered. Can someone explain to me how does the “point giveth, point taketh” system works? I am really curious.

Edit: thanks for the replies! Now I know that I have to roughly win some rounds to keep up with the points.