Said competitions are run sans collar, let alone off leash, usually in unfenced environments, with hundreds of people and dogs along the sidelines. Training the dog to listen to you, always, is critical.
After some failures, in the first year, I ended up locating a bird dog trainer and working with him, using an radio collar, mainly so that I would know how to safely and effectively use it. (I'm no great fan of these collars unless the handler puts the effort into learning how to use them. You can easily screw up a dog if you don't.)
Used correctly, an electronic collar is self-reinforcing. Every time you give a command, the dog obeys, and the dog does not get a shock, reinforces in the dog that obedience results reward. Truth is that after the initial introduction, the collars should only very rarely need to be used.
I several times called Bear off squirrels, at times when he wasn't wearing the collar. But we'd work together on agility and on obedience, for up to an hour, several times every week.
Like I said - it doesn't come free. It takes work.
