Alterac Valley: Rush Enemy Base, whoever Gets there first wins. If it’s not your team, Leave.
Isle of Conquest: Rush Hangar, whoever gets it first wins. If it’s not your team, Leave.
Ashran: Rush Solar, whoever gets it first wins. If it’s not your team, Leave.
Wintergrasp: Rush Sunken Siege, whoever gets it first wins. If it’s not your team, Leave.
This is basically my experience with battlegrounds roughly 90% of the time. And you can see a ton of people will leave at these moment, becaue the battle is already determained within minutes of the match beginning.
Blizzard said they would like to move the Focus of PVP back to Battlegrounds in The War Within, but somehow, I feel this idea is gonna get scraped or forgotten, when they realize that basically every single Battleground needs to be remade from the ground up, as they now also needs to be built with Demon Hunters and Evokers in mind, which brings a whole new movement set to the table.