IDIOM ►

keep the ball rolling, going

Meaning 1
to continue playing or rolling the ball (so your opponents cannot get it)
Sentence 1
Don't let the other team get the ball. Keep the ball rolling.
Meaning 2
to keep something going, to continue to work on something
Sentence 2
Jill, it's your responsibility to keep the ball rolling on the ads for our new account.

Derivation

to keep the croquet ball rolling so your opponent cannot get his turn