Matchmaking
The current meta with the game has 2 solo laners, a jungler and one duo lane. with the positions being solo top/solo mid/'marksman'/support/jungler now generally speaking when you load into champ select people shout out their positions immediately and most of the time everyone gets something they can play. but not always. now while this does encourage players to diversify their positions (which is good) it also has resulted in two different ways of thinking in champ select. first call first get and select order. i'm not sure which riot thought would happen if not both, but it does occasionally lead to players bailing out in champion select because they got stuck with support or jungle or adc which they couldn't play. or you end up playing a position that you have little experience in and then players yell at you in game. Normals is just practice. but Ranked it matters a little more, at least if you care, which if you don't. you should just be playing normals.
but my question/idea is. why not have matchmaking help in the selection process. add toggles/boxes so that players may select ahead of time which positions they would like to play. they could select as few as one or as many as 5 (zero would also be selecting all 5) that would players who only want to play mid get those mid match ups and practice/excell at that position. i for example have no preference most of the time. but when playing ranked i prefer to play mid/top or support. this would increase champion select wait time by a good amount. probably a lot. but you could always unselect your preference and go for the shorter wait time. i for one would rather wait 3 or 4 minutes to be able to play mid or top when i'm attempting to practice those positions
there will be violators. some will pick out of position and they can be punished by the tribunal. remove their ability to choose to play that way.
alternatively, there could be an automated tag line when you enter champ select that states your preference. this would remove the first call first get portion of it which can result in childish behavior and instead put it all in pick order.