I've been a rogue for a while, played to 1.9k with frostmage and 2k with dualrogue anyway a trick most mages use at high rating is the counterspell bug.
What you do as mage is; When you see rogues vanish animation (2 arms going up kinda thing) You immediatly CS this breaks the vanish and rogue can be wtfbbqownedlolz.
This is confirmed by me. Feel free to test and post here if it works too.