To go, or not to go.

"Shall I go and fetch that ball, or not?"
"Will I get a treat if I bring it back, or not?"

"Probably not, I'll just stay here and watch Bud exert himself chasing after the ball."

Poppy will only play ball for so long, I can encourage her to chase after it for a treat, but again only for so long. Bud on the other hand will chase a ball until he drops.