My wife's Holy Priest got ganked on the Throne of Kil'jaeden the other day by a full Season 3 MS Warrior. She grouped with a Shadow Priest who was questing in the area and had also fallen victim to the bloodthirsty Human. They got ganked a couple more times while I took my Shaman over to lend them a hand. We managed to take down the ganker several times but not before he almost killed the poorly-geared Shadow Priest. Every time that the Warrior would rezz, he would immediately Charge the Shadow Priest and proceed to Mortal Strike him to within an inch of his life, despite getting heals from my wife's Holy Priest and my Restoration Shaman.

After several more tries, the Warrior mounted up and proceeded to taunt me away from the group, the only one he hadn't yet ganked, but I simply brushed him off with a /bored emote. My wife wondered why the Warrior kept on going for the Shadow Priest instead of herself. It only made sense, I replied, pointing out that the Shadow Priest was the most logical target considering he was undergeared. My wife countered that she wasn't equipped in PvP gear, either, but I reasoned that since he'd killed her once, he knows she's not specced Discipline because he's seen Spirit of Redemption pop up. That meant no Pain Suppression, and that there's no way she could heal through his damage.

One of the most crucial skills in PvP is choosing the right target, and encounters, matches, are won and lost through choosing the right target. This necessitates a full understanding of the limitations of one's own class, a moderate knowledge of other classes, a familiarity with gear, and an awareness of one's surroundings. It's rapid threat assessment and measured response. Almost every encounter will be different, even with the same players involved. Even with a lot of experience, choosing targets in PvP can still so often go wrong.