I think it is strange that we can have a game where you have a leaver/afk and the other team ends it in 12 minutes and that game would lose you 25+ LP. On the flip side, a long, well-fought game just gave me 14!
I am not too sure on the algorithms that decide the LP you get, but when vice versa happens (I stomp them, or lose a hard fought game) I respectively gain little and lose a lot.
Please tell me that game length is not a factor!
It is not, I'm not sure the exact ratio, but depending on your MMR you will get more or less depending on where you are. Think of the old elo system, only hidden. Like with the elo system, if I remember right, silver was 1400 elo, elo is still in the game in theory, but it is a hidden value called MMR now. Now let's say your elo(MMR) is lower then your rank, like you are Silver 5, but your elo(MMR) is only 1300, because of that, you will gain less LP for win, but your MMR will steadily increase until it evens out. All in all, as long as you have a 50%+ win rate, you will go up.
MMR > division = more LP gain, less LP loss MMR < division = less LP gain, more LP loss Purple side win = More LP gain
