Does anyone have an idea of how the point system works?

In ranked its very confusing as to hiw the points are awarded and deducted. Today in 3 straight matches it made me wonder if there was any logic to how points are awarded. It almost seemed as if it was random. In match one, i get beat by player who had 2300 more points than I, and lose 55lp. Very next match i beat a player who which i had 320 more points prior to the start of the match, and win 35lp. This made me start to question how this worked. Very next match again beat a player that i had 900 more points and get 65lp. Im curious if anyone has any clue as to how this really works?