'A whole new ball game' is a situation which is different from anything that has happened before.
I thought I was good at speaking English in terms of day-to-day conversation. But working as a professional translator is a whole new ball game; I have to be much more accurate.
Tom says working as a manager for the first time is a whole new ball game.
I used to go jogging every weekend, but running marathons is a whole new ball game.
Don't confuse it with
Another phrase is to 'get the ball rolling', which means to get something started.
After a long time planning the project, it feels great to finally get the ball rolling.
I really don't exercise enough and want to get fit. If I go to the gym once a week, that should get the ball rolling.
According to one interpretation of the ancient Mayan calendar, the world is going to end on 21 December 2012. In case it does, Chinese farmer Mr Liu claims to have the solution: his 'survival pods', which can withstand 1,000-metre-high waves and carry 14 people at a time. They are also equipped with oxygen tanks and food and water supplies.