It's not a scientific response, but in my experience on EU it tends to be daytime Horde wins more on average, evenings Alliance wins more on average. Obviously talented players can influence events, but it's as much decent communication seems to swing it most frequently.
Weirdly there are times when I can't land a hit and other times I seem invulnerable - sometimes when vs a player with similar gear. That makes me lacking in skills I guess.
Regularly lose to Russian teams it seems.