Yes this has been kind of posted before... but here is a way better way to explain it and to basically do it.
Just go to any gate of any battleground... I didn't try this for EotS but it works for all others.
Stand randomly anywhere infront of the gate and press forward and spam jump at he same time. your character will b making small jumps over and over... keep doing this 'till the battleground begins and then simply your character will make a massive jump.
(right before the gates open like 1 or 2 secs u jump out with a massive jump and thus r ahead of all other people)
I tried this many times with about all 80ms... i got out every time... even people whispered me how i did it.
This is quiet logical to some extent but if u blame it on the fact hat it is an internet game don't forget that others have latency to so u will b first from their perspective and in yours.
Although sometimes mages and rogues do beat me to it bcuz of blink and sprint..
THIS IS NOT BECAUSE OF LAGG OR BCUZ OF "WOW WORKS ON THE INTERNET"... I TRIED THIS OUT AND LOTS OF PPL SAW ME OUT THERE BEFORE THEY COULD GO OUT...
Hoped this made it clearer...
Enjoy