I'm not great at it, but I would think to be really good at it, you need to be good at judging what kind of energy the enemy has. If you've got more energy than him, you should be able to get him to stall out. There still has to be enough distance between you and him so he can't get the shot off before stall though.
I think you'd have more luck if you can put yourself in a position where the enemy underestimates your energy state. He won't follow you up if he knows you're going to beat him. Also, people are less likely to just go strait up in the vertical strait into the merge. If you can get him turning and slowly pulling up, he can get himself into a bad situation before he knows it.
You can do this by yourself and roll over on top, but if you've got a wingman or just a group of friendlies, an enemy sitting in the air is dead meat.
Btw, I say most of this as a victim of the rope, nothing like hearing the buzzer ringing and knowing you'll be dead in a few seconds.
I reiterate: It's all about energy states.