Instanced matchmaking won't work. What would happen is people would queue in as support to get into a game because it would take longer to queue in as their desired role. They would then proceed to pick the champion they want and do whatever. Also if you clamp on type names a lot of champions who could do a role would be locked out of them.
The only thing I will comment on is the stupid suggestion about "instanced matchmaking" (I think that's the term the OP used.)
This gets suggested alot, and it's a terrible idea. There are two huge problems with it, both related to the fact that it "assumes" the currently popular metagame idea:
1. Can you play any champion in any "role"?
2. What are the "roles"? What if you want to play duo-top? What if you want to have two supports?
You want to make a formal system out of the dumb ideas people have: "WTF! You can't play that champion mid, he's a jungler!" Stuff like that. "Vayne is an ADC, you can't play her top!" Etc.
"Duo top WTF, no jungler!?" Sometimes it works good.
The "meta" should NEVER be enforced, it would make the game stale and stupid. Not just "what champions are what roles", but even further: "The roles!" are the issue. The "roles" don't exist. They're just ideas about how to play, and the ones you have in mind just happen to be the currently popular ideas. They weren't always the same, and they will change in the future.
See, I was at 900 once upon a time but then I decided I actually suck at the game and needed to improve in ranked. Instead of worrying about things I can't control, I bettered myself as a person. Mathematically I'll get more trolls/afkers/issues then the enemy team so long as I'm not an issue, so I'll continue to do my best and master what is within MY power.
At 1300 now and if I quit climbing, I need to be better for myself and for the future teams I'm in. That is something I can do and that will help me get higher. If I do keep climbing, then I deserve to get higher. Instead of saying, "I deserve to be in Gold." that little thing that rings in the back of my mind, I pick out my flaws and get better. I don't complain about things outside of my control.
If you are good enough to win your lane, take down the turret and gank take the next turret, immediately help your teammates out. Watch some of the LCS and see how 5 minute turrets happen, objectives objectives objectives. So long as you don't push your snowballing into other lanes, you're also not being a team player and coordinated with your team. If this is something you can't do because you didn't win your lane or you couldn't effectively snowball the other lanes, then this sounds like something within your control that you can improve on.
Watch replays of yourself and don't ask what you did wrong, figure out what you didn't do right. You got first blood, cool, but what if you shoved minions into turret BEFORE you B'd to push the advantage farther? Everyone seems to be in this mindset that I did "okay" in my lane, and because I simply did "okay" and we lost, someone must have sucked, it wasn't "my fault". It's never, "I didn't do great", "I could've done ____" or simply, the enemy team is better then were I'm at. League can have the best ranking system in the world, and it still wouldn't be fair so long as you don't recognize your flaws in playing, not flaws because you're a bad player, but flaws because most people reading this forum is no Challenger Tier player.
Not sure why I typed all that when it feels like you'll just skip over this, too many threads I've spent a lot of time in a honest post just for the OP to not read it at all because they don't want to hear it... but try to take this to heart even a little.
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