You want your game to be fun, enjoyable for your users, and therefore profitable. Here is my feedback on your OCE Ranked system.
LEAGUE TIERS - As you can see you have over 70% of your ranked player base in the bottom two of 6 divisions. Being in bronze is not something that is enjoyable, especially for those that should be in higher, well for many its an issue of time, even if they are skilled they dont have the time to spend to grind out of bronze. Should Gold not be the average division?
LANE ROLES - To get out of bronze easily you need to carry, this is best done from Mid, and Top, the lanes where others also want to carry themselves out of or just enjoy being powerful in the game. This really needs to be balanced, so support/jungle get as much gold/exp as the ones they are supporting.
LP SYSTEM - Lets go over an example of how unbalanced your LP system is. Lets say someone is on 99 LP like I have been many times, It requires 4 out of 5 wins to progress. The game to get to 99 LP, then 100 LP, then 2 of 3 promo games.You have now given a free win if you fail the first promo, which is great but how about giving the LP you stole. Because when you are on 99LP and you win a game, then lose 2 games guess what, you got only 1 LP to get into promos, and after failing you now are sitting on 70 or so. What happened to the 13-14 lp? This can be made up if you are on 0 LP after promoting a division, but I have been demoted straight after a promo before.
QUE BALANCE - If I am in a promo, I would like to be in a game with others that are in a promo, should I not have some sense of Promo priority, so I dont end up with Fresh level 30's doing 10 placement games, or people that have disconnection issues and leave, or people that dont want to try to win and surrender at 20. It is not a small sample to say that 10% of my promo games have someone that leaves "a leaver", you have no ability to dodge hostile players, I have had many games where you re-que and end up with someone you have muted or reported in the last game.
ABUSING THE SYSTEM - People use programs to bring up stats on the players they are qued with, to decide if they should dodge and only lose 2 lp, this is frustrating for those that have to que and pick champs for 20 mins without even getting into game. Many people that dont have the time but dont want to be bullied by friends being stuck in bronze, resort to paying a 3rd party to play on there account to get up in divisions, where as I dont think this is so bad, but the fact that these company's employ DDOS attacks and other methods to rig the games they want to win as time is money.
LANGUAGE - I will put a small note here about playing with others that dont speak english, or I dont speak there native language. I understand why this is needed to have a larger player base, and to save costs on running a server. Just be aware if you are going to grade our ELO/MMR vs NA and EU then take this into account. When I transferred from NA from Silver 2, I was placed Bronze 2.
Thank you for listening, I dont normally post but these injustices have bothered me for 5 years.
See you online.