Noun
(cricket) A cricket ball never previously used in a match; a replacement new cricket ball taken by the captain of the bowling side at certain specified times during an innings.
(tennis) Any of a set of replacement tennis balls issued at specified times in the professional game.
Source: en.wiktionary.orgLife... is not simply a series of exciting new ventures. The future is not always a whole new ball game. There tends to be unfinished business. One trails all sorts of things around with one, things that simply won't be got rid of. Anita Brookner
The web site and the Internet are a whole new ball game. Johnny Ramistella