At approximately 2 hours, 27 minutes into the Big One for One Drop broadcast on ESPN today, Antonio Esfandiari and David Einhorn were in a hand that checked the flop and turn. And then on the river, Antonio (1st to act) asked if he could open fold.

Jack Effel says Antonio can fold, but both players must show their hands. I couldn't hear the conversation between them after that because the announcers were talking.

Does anyone know what Jack Effel's reasoning was behind requiring both players to show? And whether this is a rule newly put in place, or whether this is even a rule at all?

To prevent collusion?

Surely he could just muck his hand if he wanted to. Why did he have to ask permission in the first place?

I wrongly assumed that everyone else also watched the broadcast. To clarify, here is the situation.

The river card has just been dealt. Antonio is first to act (of two players). Before acting, Antonio asks the TD whether he can fold (instead of check or bet). The TD then says that Antonio may fold, but that both players would have to show their hands. So Antonio then tabled his hand and folded, which forced Einhorn (the other player) to also table his hand. Showdown was never reached.

My curiosity about this ruling lies in the fact that Player A may exploit this situation by folding (instead of checking or betting) in order to force a gain of information (Player B's hand) that he ordinarily would not receive if he acts (checks or bets) as normal.

I understand that obviously by forcing both players to table their hands, it may expose chip dumping. What I want to know more specifically, if anyone here knows, is

1. Is this actually a rule? Or did the TD come up with this ruling on the fly?
2. Other than to expose chip-dumping, was there any other possible reason that the TD required both players to show their cards? (Not that exposing chip-dumping isn't enough of a reason by itself.)

The reason I ask the above is I have never seen this rule applied in a non-showdown situation before, and I am curious about its origin and purpose.

The collusion argument is stupid and illogical... if they were colluding like this, they could just agree to have the player out of position, Esfandiari in this case, check-fold to any bet and neither would have to show their cards. Ok in this tournament every hand is televised so they'd find out something was going on, but I'm sure the rule would be the same for a normal tourney.

Angle by Antonio to get to see the other's player's hand for free.

What if the other player folded as well'?

Other player can't fold can they... if you're playing HU and someone openfolds the other player automatically gets given the pot.

WSOP has a show to win rule this year, Antonio simply exploited the rule because he wanted to see Einhorn's hand. I really don't think this was an angle at all, Einhorn was being reluctant about even showing his hand to the holecard camera(even tho he signed a contract). This was merely a live pro needle at Einhorn for making a big deal about pros being able to see his cards.

I am not sure if by showing his hand face up when action was on him that would force Einhorn to open his, surely if Antonio open his hand in a heads up situation the action is still on him and he is still required to Check, Bet or Fold regardless of the fact his cards are now face up. If he checks then all Einhorn has to do is either Check and then open cards as per normal showdown or Bet and make Anotonio have a decision. I think the fact that his cards are exposed are irrelevant to this as he chose to expose them himself.

If the TD did insist that Einhorn opens his cards I do not believe this would be a correct ruling.

Just my opinion on this anyway.

online
But what if he does not want to show?

The commentators commented on the fact that when Antonio folded he also read Einhorns Hand. I think he said 'your ace is good', Einhorn had AK. Maybe it was a bit of meta game to intimidate the amateur.

Not mentioned though was that Einhorn was refusing to show his cards to the hole cam. Since the players were learning the hole cards 15 mins later they were annoyed that he wasn't showing and said so at the table. Maybe he just wanted to force him to show.

Soon after they seemed to come to an agreement to show all cards at the end of a hand with more than one bet.

all players had a rule that they were going to show hands at the end < dont know if that had anything to do with it

The TV commentator said the players had an agreement they'd show their hands (for every hand), this may just have been one instance of it