The alpha roll was repopularized in the book 'How to Be Your Dog's Best Friend' by the Monks of New Skete which came out in the late 70's or early 80's. Before that it faded in and out of popularity and use.
I'm told that in the latest edition of this book the alpha roll is no longer included as a training tool.
To perform the roll you're supposed to grab the dog by the excess skin around his neck, force him backwards into a sit and then roll him to one side. Some trainers advocate rolling him all the way onto his back. The idea is that you're simulating something that dogs do to one another when the dominant dog is displaying his dominance to the submissive dog.
But it's just not so. If you watch some dogs at play, for example at a dog park or the zoo, or watch the Discovery Channel. Use a Video Camera (or record the TV) so you can play it back several times. You'll see what at first looks like an alpha roll but when you examine if carefully it's not even close. When dogs do this, the dominant dog doesn't force the submissive dog to do anything. It's the submissive dog who's doing all the work. The dominant dog puts his foot up on the submissive dog's shoulder or back and the submissive dog rolls himself under the dominant dog.
And so when you do the alpha roll thing you're doing something that's completely foreign to the dog, rather than something he's familiar with. You're showing him that you're bigger and stronger than him, but he already knows that. It's the action of a bully, not a fair and just leader.
Real dogs in the real world don't do anything like this. When a submissive dog rolls himself under the dominant dog it's because he's showing submission. This isn't a case of the dominant dog showing dominance. He's already done that merely by placing his foot on the other dog's shoulder or back and that's the reason that the submissive dog has gone down.
And so the alpha roll as dogs do it, isn't a display of dominance; it's one of submission, where the submissive dog is doing the work. It starts with the dominant dog putting a foot up but the rolling portion, the part that the alpha roll is simulating, is done by the submissive dog. The alpha dog is only present by virtue of his personality, he's not rolling the other dog at all.
If you do this to the right dog (wrong dog) he'll eat you for your trouble. And since the closest thing to bite is your face, that's where you'll get it. It's hard to give an out command when the dog is holding you by the face!
Since 1979 I've been training some of the most dominant, most aggressive, most fearless dogs on the planet. I've never found the alpha roll necessary. I've done it once or twice when I was new and someone told me that I should. It didn't have the desired effect and after thinking about it and talking about it to the right folks, I discarded it.
Domesticated dogs only rarely submissively pee to other dogs, especially members of their own pack. That's reserved almost exclusively for their humans who, without realizing it put the dog into an overly submissive position and the dog has no choice. Some dogs, ones who are extremely low in the pack pecking order, such as the omega dog may show submissive urination every time that a dominant dog (that's every other dog in the pack) approaches, but that's still a rare display.
Your height already provides a cue to the dog that you're dominant. There are some trainers who will tell you to never let your dog stand over you but I think that you need to permit this once in a while. Some trainers tell you to NEVER allow it. But if you think about what I do and how it gets done, training and working police service dogs, you'll realize that it's good to, once in a while get on the ground with your dog and play with him as dogs play together.
Let me paint a picture for you. Imagine the type of handler who's been trained that he has to alpha roll his dog once a week to remain in the alpha position. Also imagine that he's been trained never to let his dog be on top of him. The handler gets into a fight, and like most fights it winds up on the ground. He calls his dog for assistance and as the dog runs to the scene he sees the alpha dog on the ground, someplace he's never seen him. He remembers that this alpha dog has been rolling him every week since they've been together and maintaining his alpha position with brute force. He sees this alpha dog fighting with a complete stranger, someone who's never hurt him or done anything to him before. Do you think it's possible that he'll think that NOW is a good time to challenge the alpha dog and to try to the top of the pack? Could be!
Wouldn't it be better if that dog had been lead by a fair and just pack leader who didn't use physical force to maintain his position? Since the #2 dog has rights that the #3 or #4 doesn't, wouldn't it be better if the dog thought of himself as the #2 dog in the pack not just as any subordinate animal.
If you alpha roll your dog consistently he may become afraid of you. That's not a good relationship, particularly if you want the dog to work protection for you. He'll do it but you might find him "attached" to you occasionally. I think that the best relationship between the handler and the dog is one of mutual trust and respect. A dog that's rolled won't trust the handler, he'll fear him. This may not show up in the form of the dog cowering from the handler, except in extreme circumstances. But there other, much more subtle ways it shows up.
Want to be an Alpha? Begin by acting like one. Stand up tall and act like a leader. Notice that most dogs are submissive to a good trainer just by him walking onto the field. That's because he knows how to stand, carry himself and talk as a leader. He hasn't alpha rolled your dog. He hasn't kicked your dog's butt, but your dog knows, at a glance, who the alpha is. Use a normal voice. When adult dogs play with other adult dogs they use a certain tone of voice (bark). When puppies play with adults or other puppies pitched they use a high pitched yip. If you use a high pitched voice when playing with or praising your adult dog how do you think he thinks of you? As a mature adult capable of leading him? Or as an immature pack member? Now I'm not saying that he'll immediately become alpha if you praise or talk to him in a high pitched voice but I am saying that you're sending a mixed message to him. One that can put some doubts in his mind as to your exact position in the pack.
Being accepted as the alpha doesn't mean that you're the biggest, baddest one in the pack. Anyone who teaches that really doesn't understand what it means to be alpha. In human packs, without the politics, often it's NOT the biggest or strongest one who leads. It's the one who exhibits "leadership qualities." In dog packs it's the same way.
Another part of being alpha has to do with food. In the wild the alpha leads the hunt. He decides which animal the pack will kill and when the eating will begin. Generally you provide the food for your dog so that helps him think of you as the alpha. I suggest that when you get a new dog you spend a couple of weeks hand feeding him. That establishes, even more than just putting down a food bowl, that you're providing his food. Don't let him crowd in and 'demand' the food. Make him stay at a respectful distance and wait for you to give it to him, one handful at a time.
Another way to be fair and just is to be fair with your correction level. The Ecollar is perfect for this because it allows you to dial in exactly the level of correction that your dog needs. Not too high and not too low. It's difficult for the average handler to consistently give the exact level of correction that a dog needs with a leash and conventional training collar.
Play is another way to get this but not the form of play that has the handler throwing a ball for his dog. Watch the Discovery Channel or spend a few hours at the zoo watching wild dogs play. They run, they bump shoulders, they throw hips into one another. Their interaction is quite physical.
Another way to establish dominance and one of my favorites is through yielding. I stole the concept from someone who stole it from horse trainers. Yielding is based on the idea that a submissive animal will move out of the way of a dominant animal. Almost ritualistically the dominant animal will force the submissive animal to give way, even if he doesn't need to. It's just a reminder.
To do this have the dog on leash and start walking into him. Going head to head is probably best, at first. Don't give any commands, just head towards him. When you get real close start quietly saying "move, move, move," Don't kick him and don't bump into him unless it's absolutely necessary. What you are trying to do is to force him to move by the power of your personality. When you do this make sure that you're looking like the alpha. Stand up straight, shoulders back, head erect. Don't stoop forward to look at your dog, that communicates to him that you're not an alpha. Some may need to practice this in front of a mirror before they try it with their dog.
As soon as he does move, step back and praise him lightly. Not enough to break his concentration, but enough so that he knows he got something right. You should see a relaxation of tension in the dog's body. Think of your forward motion as applying pressure. Pressure that the dog can relieve by moving away. At first just one or two steps will relieve the pressure, but as you progress he has to move more to gain relief.
As the training progresses you can approach from slightly off to one side, then directly to one side, then from the rear quarter and finally from the rear. When you start this have him move several times in a row. Once he's caught on you can go to about ten times a day.
This is so subtle that many people believe that it won't have any affect on the dog, particularly one who's very dominant. But it will have more and better effect than a dozen alpha rolls. And it will establish your position with VERY little chance of a handler challenge or an attack on the handler.
If you're going to do an alpha roll you'd better pick the dog you do this on carefully and you'd better make sure that you can kick his ass. You'd also better be ready for a trip to the ER, because sooner or later you're going to miss.
It's really too bad that some people are still caught up in using force all the time for all of their training. It's not necessary. It's hard on the dogs, and it's hard on the handler. AND most importantly it doesn't give a good a working relationship with the dog as more subtle, but still effective methods.