Aaaah, a fellow labradorian.
Well, i will try to keep this short, i know i've said this before on this forum.
But, we have a 3 yr old lab, we did puppy class, then tried obedience school at 6 mos... didn't go well, he had NO attention span. We tried every kind of collar and leash available.
Nixon went through the same thing your dog is going through about 8-10 months old, he made me sooooo mad, and i felt out of control on every walk, it wasn't fun anymore.
I bought Brad's e-book about a year ago, but we've been busy, and then couldn't get into his classes until now.
So, my advice to you, is buy the ebook, get a martingale collar, and tie that labby around your waste... we did it just around the house for a while, because i was afraid to take him outside, for fear of my life (AKA pulling)... but once we started, i couldn't believe we hadn't tried this before... Then, try to get into his street safety classes if you live somewhere where they are available.
Nixon used to be good off leash too, and now he's not as good.. but he's getting to be really good ON leash, and we'll work up to being off leash again, when he can be trusted a bit more.
Get your lab to pay attention to you, by doing some umbilical training, in and out of the house... and see if that makes a difference.
Our biggest issue is coming when WATER is in the picture... another hugely frustrating issue. : ) Maybe by the time he's an old man, he'll have calmed down and obey me.
Good luck!!!!
Oh, i forgot... one thing that made a big difference too, is not talking to the dog for a couple weeks.. its really hard, we still gave him affection, but no talking. he'll pay more attention to you when you do start saying things like sit, stay, come.. .the important stuff.
And, don't let him beat you through the door, or up and down the stairs.. you win.... feed him on your time, not his... (we were bad for that, he'd come at 4pm and lick his lips at us, and we fed him... now we wait till he stops, and forgets about it, and then we go over and get his food).