Okay here it goes, u all know how horde are overpwred in pvp with FROST SHOCK, TOTEM SPAM and so on and when alliance have the flag, horde clusters up to prevent alliance from getting it to their base, they mainly cluster up at tunnel and the side entrance.
here is where this exploit comes into deal.
Attachment 87
follow the red line and do the jump+forward thingy and there you go, alliance third entrance.
credit goes to our newest member mikomido as well for showing me this ingame =),