My girlfriend's 7 y/o Border Collie, Waya, isn't the fastest, but she's fast enough:
I laid down on the ground and told my girlfriend to throw the ball at me. The ball hit me a couple of times, but I did "get the shot," and Waya was agile enough to avoid colliding with me.
The above 4:5 aspect ratio crop isn't the 16:9 aspect ratio I had in mind, but this actually looks alright on my 4K monitor. A more aggressive 16:9 crop is (I think) a bridge too far, even though her eyes are within the focus plane she is moving so fast that at that distance there is significant motion blur and the shutter speed should have been closer to 1/5000s rather than the 1/2500s I used -- next time I will know better.
Anyway, the 16:9 crop is manageable for smaller screens:
