playing any online game by yourself still counts as playing alone. Hell, even when I play Reach online I'd call that playing alone.
When I was playing solo to level or for whatever reason, absolutely. But battlegrounds are a bit trickier. Alterac Valley (or any battleground) isn't exactly a solo experience. Although, with the general lack of coordination on most teams it can certainly feel like one.
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xp1337: Don't you wish there was a spell-checker that told you when you a word out?
GotD (219/384) Melee v FFX