A big bet game is one that is played without a pot limit or any fixed limit at all. It's betting structure is such that a player can bet with any amount of money which can be wagered or placed into the pot at the start of a poker game. This style of play is often favored by more experienced poker players. These are players who believe they have the wits, wisdom and wherewithal in betting funds to go on the offensive without having their challenge capped for any reason.
So in any fixed limit game whose rule states that the limit is greater in the rounds ahead rather than in the early rounds has the higher amount is called a big bet game. "The last game we played was promising from the outset, only that I held a hand with 8 big bets which proved otherwise." Therefore any game of poker that is played with a betting structure that allows only pot limit or no limit can rightly be referred to as a big bet game. Because of the same wagering structure, it could also pass for the big boys' game.