Here is our border collie Jojo. (with the perfect 1/2 black 1/2 white face) She love playing fetch, especially with the soccer.
Playing ball is her life. She would literally play ball all day long - with maybe a few breaks in between. We usually get tired before she does.
We've slightly deflated the ball so it's easier for her to get it into her mouth.
There something about a ball that is just wired in her brain that captures her attention. When we go for a walk, she is captivated by tennis, basketball or soccer games being played. I guess she thinks she should be included.