have something on the ball
To be attentive, knowledgeable, and quick to take action. Primarily heard in US. I'm so glad that my assistant has something on the ball because I'm too scatterbrained to manage my schedule on my own. I can't believe Molly got that report done so quickly—she really has something on the ball.
have something on the ball
to have a particular amount of smartness or cleverness. Both John and Mary have a lot on the ball. They should go far. I think I'd do better in school if I had more on the ball. I learn slowly.