Add a ping test before ranked queue
Many players will agree with me that playing with a teammate who is reconnecting every 2 minutes is very frustrating and tilting. Not to mention that most likely you will loose that game since its a 4 vs 5, and the lagging teammate might have fed the enemy laner while disconnecting. So what do I suggest? Add a ping test before every ranked queue. If your ping is above a certain number, say, 140, you cannot go into queue. Another addition would be that if the person does not have a somewhat stable ping, they arent allowed to go into queue either. This is to ensure that people will not ruin other players' games by ranking with lag. This could improve ranking drastically.
I would also like to mention that I meant to make this suggestion in the LAN board, as my main is over there, but it seems that a "suggestions" or "gameplay" section is lacking over there, I would appreciate it if Riot could give the board a look.
Thanks for reading, I hope you have a lovely day.