i am 1583 elo and when i played on my friend's account at 1k elo, i was stomping them by playing xerath mid which AND it was my first time with him, i dont even play mid lane either

40 games isn't necessarily a large enough sample size.

http://en.wikipedia.org/wiki/Elo_rating_system
Considering that they 'were' using a system meant for two player games, it's going to have flaws.

You have a virtually 50% winrate in both scenarios (only 1 or 2 games off) - that suggests to me you're not carrying at all, but you're not dragging down the team.

People's skill is not a factor or one word - you can't just say a 800 is bad and a 1500 is good. You may be someone who's good at not losing games but bad at carrying, for example. If you play safe at 1500 and don't take many risks, you may find yourself winning more often than not. If you play safe at 800, you may lose more than not because you're not taking advantage properly.

So you lost 21 won 19 and lost 8 elo.

You won 22 and lost 18 and gained 19 elo.

Seems perfectly fine to me, where do you see a flaw?

People think 40 is not enough and Riot claims that if you play many enough you can reach your true elo - it means most of the players will never play enough to reach their true elo, not even those pro gamers who have played merely hundreds of games in ranked.

I honestly cant see how a 1500 cant get out of 900...

I literally had a friend that was CONVINCED, he was in elo hell.. he played a couple hundred games and told me not a chance his account would get out of 1100 elo.

So i bet him if i could get his account above 1500 elo he had to get me the highest amount of riot card in his local store, after 2 weeks i was 1507 and he is an irl friend and payed me 50 dollar riot card, since then he has played season 3, his account is now labled as "unranked" meaning he has dropped back to where he was.

Your skill level , your understanding of how to finish games, how to make people pay for bad play. Its very much an individual effort, combined with a solid team performance.

This is gaining elo.

There is no way a 1500 player shouldn't stomp the **** out of 900 players. OP either got incredibly unlucky in his 40 game sample or he was trolling his teams somehow in the 900 Elo games.

The discrepancy between good and bad is so trivial in this game it's actually laughable. People define "good" as playing in a linear, traditional fashion ("0 cs" supports that buys revere and wards all game, adc champs that literally have carbon copy builds), and "bad" as anything that diverges from the norm. I'm considered a "bad support" by peoples linear interpretation of the role, but interestingly enough I have more assists in one champ than many others do with a single champ in their roster. (literally over 2k with ori alone).

ELO is the measurement of how long you're willing to play this game and how lucky you are in matchmaking, at least up to a certain point.

Up until 1800 or so. I don't remember the exact number. Plenty of streamers and friends alike have suggested/agreed - Elo is random from 1100 to 1600. The only difference is above a certain point you stop getting those players who completely feed and have no idea how to handle a lost lane, and it makes it easier to carry. The average skill level of players remains the same.

Also the concept of "if you are truly more skilled than your ELO you will win on average." doesn't always ring true. If you are "truly" 1400 in skill level, and playing at 1200, and you get laned against the guy who is "truly" 1800, what is there to be done? This game does not have such a high skill cap that you can just outplay everyone at your elo, it doesn't work that way. Sure a high elo player can carry any low elo game, but they're 2k elo players or higher. In their situation, they're basically the 1800 playing against the 1400 in a 1200 game.

I hope people know where I'm coming from because I feel I didn't word everything right. Basically you can lose games regardless of your skill level, and especially early in the season or around the 1100-1300 bracket with new players rushing in, elo has always been random. A toss up. Unless you're *very* skills (can carry yourself 1600 or higher) it will take you hundreds of games to gain significant elo, and you can lose it in a matter of days with bad luck.

Another concept is the concept of character elo (BP vs PP in Street Fighter comes to mind) and I bring it up in every elo thread. I can always carry as Ryze or Varus, my Ezreal mechanics are decent, I like the play style of Ziggs, however whenever I play Jayce I win lane lose game because I am just not skilled enough with him yet. However I love playing the champ and always feel like maybe this is the game I can carry. I'm like 40% with him even though I don't believe I'm *bad* with him. If I truly wanted to gain elo I would just grind Hecarim/Ryze games all day every day (Athene lol) because I only have 70%-ish percent with those champs at various points.
Many of the people in your ranked games might be 65% on Lee Sin top, yet he locks something like Renekton first pick top to try him for the first time and gets crushed by a Kayle. You could even have someone who only plays a mid like Ahri (70%) but no one was willing to trade, and he picks and has to face a Kassadin or a Talon or something. You could have your bot laner get fed due to your ganks/support but then lose anyway because they can't actually position well in a teamfight.

You can have the best mechanics on one champion in the game (Cris on Riven, Inverted Composer on Singed come to mind) and play only those champions and carry yourself to top tier, but there's no question you have lower skill on many other champions and will, on average, lose your lane in any other role.

Plenty of things can happen that keep your Win/Loss % roughly 50% regardless if you're 1100, 1200, 1400, or 1600.