sally that reminds me off a neighbour that bought a working sheep dog the seller demonstrated the dog working excellent just what he wanted got it home diddly squat it was the sheep that were trained the dog just ran at there back 
I've heard that story a number of times. In my experience, it's usually the handler...

Seriously, some collies will work for pretty much anyone, but even the very flexible ones take a while to bond with a new handler. It's unrealistic to buy a dog and expect it to work immediately for you the way it worked for the handler who demonstrated it to you - or even to work for you at all, at first. What is being demonstrated is the dog's capability to work with a handler to whom it is bonded and who knows how to handle it.
BH had to buy a trained dog a few years back when his only collie unexpectedly died in the night, just before lambing time. A nearby farmer had a bitch in training with the local sheepdog trainer and said BH could have her if he wanted; his own need was not so urgent and he could have another one at a later date. We saw her, she seemed fine, we brought her back to BH's farm. (I didn't live here then.)
A few days in, BH asked me to see what I made of her, he couldn't get her to do a thing. Within 10 minutes I had Come Bye and Away, Lie Down, That'll Do, and Walk Up. Not great, weak on the sheep, not good flanks, but responding to the commands and working the sheep. Thing is, I've been trained by handlers who trial, I know how they command the dogs and hence how our local guy had trained this bitch to respond. BH, like most farmers, does things his way - and Mist didn't speak his language yet.
By mid-summer, BH had her doing what he needed, and now, they're a real team - and I can't get her to do a thing!
