My understanding is that AP champs are better early game than AD, so having your AP go solo mid is advantageous because it allows the AP to gank the side lanes better than an AD can

also it allows the ap carry to get your own blue buff easily

Why do AD go bot? There's numerous reasons.

A support babysits the AD carry because AD carries scale the best with items than anybody else. So much so that feeding the gold to one character and forgoing gold on the support is effective enough to create the 0cs meta. AP on the other hand scale through levels better than anyone else. Midlane is the shortest lane in the game so the xp gets to mid faster. In addition, spells on APs generally have higher ranges than attacks on AD carries, allowing strong harass on the frailest type of champions.

Mid is easier to gank than bottom. If mid gets ganked and the AD and support get killed, there is 1 person top, the jungler, and 1 person bottom to defend dragon. This means 1, maybe 2 people are in position depending on the junglers location. This creates a 4v2 fight for dragon. With AD/support bot lane, if mid falls, it is a 4v3 which can cause enough pressure to stop the dragon attempt.

Reasons for why AP carry goes mid:

1) Easy Access to Blue Buff
2) More levels gained (levels scale better for AP than for AD as AP relies on spell damage which increases/lvl whereas AD relies more on items which are bought through farm)
3) it is a easy lane (comparatively) to survive against ganks. Look at top/bottom these have more distance in between towers so there is more of a "danger zone" in between them. this naturally favors solo players more as they can tower hug/ farm a lot easier without being in danger of being ganked. imagine trying to solo bot. you'd either be zoned at tower or you'd get ganked ALONE and die.

ITT ppl who dont understand the OP

he isnt saying solo mid AD carry, or solo mid support.

he is saying solo bot lane AP carry. duo mid AD carry + support

since an AP carry usually has better escapes than AD carry, mid is harder to gank, and supports have more room to ward effectively. AD+support mid would work, or atleast would work if the other team goes AD+support mid. because the AP bot would otherwise be vs 2 and proly lose. 2 mid would have mid even more protected.
AP bot would favour purple team because of blue buff placement. but AD carry mid has better access to red buff (atm favours blue team)

on top of that, its just a metagame. it will shift and maybe soon we will see AD carry + support mid. just try it a few games and see if you can win with it, then maybe show a high ELO person or post your success on GD. who knows, might be the normal one day.

1) Support doesn't need to go mid to cover their warding duties. While support has access to top river for warding, there's no point warding Baron during the laning phase because no one is strong enough to take him. In fact, they're welcome to try! Whereas Dragon IS up for grabs. So Support doesn't need to have access to top. Warding baron at level 6? Why!?

2) You don't send AP mid because they're AP. You send them mid because either you want to leverage someone with strong mid-game scaling (either by early-mid burst like LeBlanc, or by a strong ult like Pantheon or Karthus) in the position where they have the best access to top and bottom lane ganks...... OR.... you're running a champion explicitly designed to counter such a champion (Kassadin, Talon, etc.) It has nothing to do with 'AP carry' per se... it has everything to do with 'Does this champion have mid-game potential to wreck other lanes.' Pantheon goes mid, not top, because you want his ult to reach all lanes, not just mid.

3) You want two players laning close to baron, so while this reason alone makes mid or bot viable for a duo lane. However....

4) AD carry has the strongest -late game- power. Unless he gets fed, he's not going to be able to roam around and gank with impunity. That means he's unable to leverage mid's advantages in the same way that your standard mids can. So there's no -reason- to put him mid unless you're doing so as a counterpick against a champion that CAN leverage mid. But in those cases, you still won't duo lane mid, because such counterpicks need to scale quickly and having someone there splitting xp doesn't get them their skills quickly.

I played against a team

Irelia top

Karthus + soraka mid

And ad carry +alistar bot lane.

Surprisingly wierd but amazing, needless to say.. we lost

looks like quite a few people have provided answers

i'm sure theres some people who will still just think "its a silly meta and has no point" but thats just a lack of understanding

with that being said if you're playing standard and not ranked chances are you can do anything and win, i've played games where someone tried to troll me so we double ap'd mid and we won, similar thing happened and i solo'd bot with nidalee vs 2, we won, i've also played standard team comps and lost etc. the thing about standard and also lower ranked elo games is that the meta doesn't matter cause most players don't understand it and/or they're just bad

honestly you can do almost anything in standard games and still win if you're good, and thats actually the biggest reason so many people in ranked are bad cause its hard to realize whats a good idea and whats a stupid idea playing in standards cause anything can seem good due to bad competition

Ap mid to get blue

and 2 bot because theres more distance between the turrets

Ad does go mid when kass mids

oh god.. so much misinformation in this thread. The real reason is for blue buff being close. Blue buff is close for purple team bottom, but if they put their AP mid there, they will get zoned badly by the enemy AD + support because there is so much distance between the two towers.