Meaning 1 ►▼
to continue playing or rolling the ball (so your opponents cannot get it)
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
Jill, it's your responsibility to keep the ball rolling on the ads for our new account.
to keep the croquet ball rolling so your opponent cannot get his turn