Ok I will post a short role guide for more details you will have to dig a little.
TOP: Long lane - far away from where most of the action is - that's why prefered summoner is TP.
SInce the lange is so long, anyone coming top will have an easy time getting a kill. Which is why you put Tanky Champs up there that CAN deal with that. (And some fighters that can 'abuse' the weak earlygame of Tanks)
JGL: One word: TEAMGOLD - Ignoring the JGL might work in low-level games but wil result into a huge Gold-disadvantage for the team running 2-1-2 since they dont have the JGL resources - the 2 guys will be underleveled since EXP from minions is shared to everyone around them. AND the opponent JGL will have an easy time diving your bot and mid over and over again since he has nothing to fear when doing so.
(In theory the most diverse role where you fill in the type of Champ your team lacks, Assassin/Tank, Good, clears and good ganks are necessary for a Jungler)
MID: The short lane in the middle of the map - suitable for fragile/immobile champs since their escape route is short - those are usually mobile in one way or another or have high CC on top of huge DMG they can use their position to roam to top and bot, getting kills for their team.
Best lane to get EXP fast which is why Mages are Main class on Mid (Assassins are played theirsince since they work similar in terms of strenght but also counter mages)
BOT: 2-2 Since you have to place your 5th guy anywhere. Shared EXP so Champs that get stronger with Level are kinda bad here. (Mages/Assassins) That's why you're using Champs that scale hard with Gold. The ADCs who need ALOT of stats from different items to be usefull (AD,Crit,AS,Pen). And give them one guy who does nothing else but making sure their partner can do nothing but farm for 20 minutes before than winning the game to to his high DMG.
The Champ that's starving in gold - the supp - should be someone that doesnt need much gold OR Level since it's shared - so either a Tanky guy (Tank stats are cheap), a CC monster (Items dont affect CC) or someone with really high base DMG or ALOT of other Utility.
Reading this you may ask why Top and Bot don't switch.
That's because of the Dragon - this guy is the most contested and valueable objective in the early-game. That's why you put the 2 guys bot since 3 people (Supp,ADC,JGL) can clear the dragon quite fast once the opponent gives them an opportunity. (After a good gank for example)
If I missed something, someone may correct me. =)
@OP HF playing League and do your selfe a favor and just ignore the guys flaming you, usually... they're just as bad.. or good.. as you are. ;)
