As far as I know, the main reason we have a mage mid and a duo bot is because mages tend to roam better and there is no objective worth taking on the top side of the map.
Well, there wasn't.
Now that we have the new monster in the baron's pit, wouldn't it be worth considering to send the ADC+Support mid instead of bot, at least if your mage is one of those who greatly prefer to farm rather than to roam (hi 
)?
Also, worth noting that most supports can roam quite effectively...
Viagrasaurusrex1 votesOne of the other reasons you have a mage mid is because the lane is short making it easier for them not to get caught out(if they're properly warding) kharthus would be fine solo bot, if you knew how to farm well under tower.(or freeze the lane.) the other ADC/support would try to pull the lane back so you could get ganked/destroyed.
Mast3rShake1 votesI thought the same thing. There are three major objectives now early game:
putting your duo lane in mid gives the greatest control of all three and allows really great roam potential making any of the other lanes a 3 man lane (4 man if u bring jungler) very quickly
