Come to the defense of a base in Arathi Basin 50 times by recapping the flag.
If you don't mind winning or losing while going for this achievement, play a rogue while doing this achievement.
Defend a flag alone and let the enemy faction tag it, sap them and then recapture it from behind. If they should trinket out of it, try to use blind and then recapture the flag.
It might take some time, and it won't always work, but it's a more effective way VS running to a node that needs help and praying you're the one that gets the recapture.