> The whole video game genre exists and is named such because of that movie.
If so, then it is ultimately named for the pro wrestling free-for-all format. The author says in the foreword that's how he chose the name for the book.
So they renamed the game from PlayerUnknown's Battlegrounds (thus why everybody called it PUBG) to PUBG: Battlegrounds. So what does the BG in PUBG stand for? The game is a real example of a PIN number!