A friend and I have a bet and after searching the internet (including Wikipedia and 'ROBERT’S RULES OF POKER', as well as asking a friend who used to be a dealer, there is still no clear answer that we can understand).
We are seeking for the official rule in relation to the case below, and if there is no official rule -- what is the dominating norm in the world (online, physical casinos, tournaments, cash games, home games -- taking ALL into consideration, what would be applied in more than 50% of the cases).
The case was: 3 players in Texas Holdem cash game.
After the Turn, the first to act goes all in. He is also the chip leader. He gets a call from the 2nd player (who is, by the way, the 2nd chip leader). The third player also calls the all in.
NOW... Must the first player SHOW or MUCK OR -- does he have a right to wait for the river (still not showing his cards), and only then decide if to showdown (or muck).
Note that the bet is only about the point if he can wait for the river or not.
Also please note -- A. If no one demands from the initial raiser to open, must he still (show or muck) BEFORE the river is opened? B. Can a 4th player who was in the action before the turn, but folded before the turn (e.g., folded after the flop) demands the initial raiser to show after the turn (after going all in and getting 2 calls), must the raiser show?
We are not seeking an answer about poker ethiquette, we are looking for the rule or dominate norm in the world of poker today. Thanks very much!