Have you had a dog who just does not fetch the ball properly-meaning they don't bring it back to you?
Here is a solution I came up with my foster dog. He would run after the ball and bring it back about halfway, and drop it there and I would end up fetching the ball too! These are the steps I took to overcome the problem.
I brought a small rug, and taught him to go on it. To teach this I brought it out and every look and movement he made towards the rug, I clicked and treated. If he got all four paws on it JACKPOT! I repeated the small incraments and in a short session he got the concept.
Next I taught him to come to me with the mat on by my feet. I put him in a sit stay 3 feet away. I called him and the minute he put his paws on the mat I clicker and treated. We started from further distances all the way from hundreds of feet! Once I was sure he got the running behavior and had to come in contact with mat everytime he ran towards me I proofed the behavior in other places as well.
Now for the fetch! I started throwing the ball just three feet in front of me. When he brought it back and touched the mat click and treat! All over again it started with just adding distance.
After about a week of practicing, he began to really get it, so I started to proof it in other places. Then after about 2 weeks, I began to fold the mat to be smaller and smaller until it finally disappeared.
He is now reliably fetching!