but I have found that my dogs recognise the incentive offered (e.g. a treat--rabbit fur ball is a hot favourite, food doesn't really do it for them) and that there is a human willing to play a game with it, rather than being reeled inIf you reel them in whilst recalling them and then use the ball and a game as the reward for coming back to you they will learn that a recall means fun and games and thus becomes a fun thing to do. The long line means they can't ignore your recall because they have no choice but to return when called.
I have a rescue terrier who had a very iffy recall and progressed to returning in a flash. We then hit the teenage stage and everything went out the window. He went back on a long line for 8 weeks and would be recalled, reeled in and rewarded on numerous occasions during a walk. His recall is back to being almost instant as long as I keep a good look out for distractions - he is a terrier after all :-) I do agility with him and have found that the best thing for gaining his attention is a squeaky ball so this is kept just for agility and as a reward for brilliant recalls.
My other dog is very food orientated and calling him for his dinner helped to reinforce the idea that returning to me when asked resulted in a jackpot reward :-)