Note added 30/9/2017: The Chair of the WBF-LC has pointed out that the Dutch interpretation of law 57D is not what the WBF-LC intended when they wrote law 57D. A clarification will follow.
In the English language (and lots of others who have simply copied it), the term “idiot proof” is used to describe designs which cannot be misused. Of course, it has has also been said that when you make something idiot proof, Darwin predicts that evolution will simply invent a better idiot that is capable abusing the idiot proof design nevertheless.
The 2017 Laws of Duplicate Bridge have been in effect for about 3 weeks now and the first case of nature inventing a better idiot has been observed. The law in question is the new law 57D, which reads:
When a defender attempts to play (not lead) to a trick at his RHO’s turn, Law 16 may apply. If his card can be legally played to the trick, it must be played at his proper turn: otherwise, it becomes a major penalty card.
The wording is a bit confusing (RHO is relative) and a reference to law 45C1 (card deemed to be played by a defender) would have been useful, but anway. What was intended here is the following:
- South is declarer, won the last trick and now leads a card from his hand.
- West is considering his play.
- East picks a card from his hand, ready to contribute it to this trick.
Note that all 3 conditions above should be met. Sounds familiar? Yes, this is a nasty habit usually from somewhat experienced players who think they are a lot better than they actually are. Of course, once west knows that east already knows which card he will contribute to the trick, it becomes easier for him to select his play. Also note that all this also applies to the case where South is dummy and declarer North asks for a card to be played from dummy.
The new law 57D was intended to deal with this case:
- The reference to law 16 says that West cannot use the fact that East knows what to play, if he does, the score can be adjusted.
- The phrase “If this card can be legally played…” forces East to play the card he has selected, even if West’s actual play makes another card better.
- The last bit “otherwise …” makes it impossible to abuse all this, by selecting a card that cannot be legally played, then say something “Sorry, I cannot revoke”.
As an example, consider this situation. ♥ are trump, South has shown 5 or 6 of them in the auction and leads the ♥Q. 
West is considering his play from ♥Kx and has to decide if the layout is as in case 1 or case 2 on the right. Let’s assume for the moment that there is actually a case to play the ♥K and return something if the actual layout is case 1 (but obviously not if it is case 2). Doesn’t life becomes a lot more simple if East shows that he already knows which card to play? And if West gets it wrong by play playing the ♥K with East holding ♥Ax and having the ♥A ready to be played, don’t you think that East wants to reconsider?
Right!
This wasn’t dealt with properly in the previous version of the laws but in 2017, the new law 57D changes all this. The TD can award an adjusted score if the right play was suggested to West, East cannot change his card if west plays the ♥K when he had the ♥A ready to be played. If East doesn’t like any of this, the solution is simple: wait pulling a card from your hand.
So far, so good.
However, it took 3 weeks for nature to invent an idiot capable of abusing this law. Here is the situation.
- South is declarer, won the last trick and leads a card. Or South is dummy, declarer North asks for a card to be played.
- West considers his play.
- West (and not East!) pulls a card from his hand, doesn’t show it to his partner, and in the process decides that he has pulled the wrong card. He attempts to replace it.
In the example above, west decided to play the ♥K but mistakenly starts to pull the ♠2 next to it from his hand.
Over the past weeks, I have seen a number of TD calls and heard remarks from players that the first card West attempted to play, should be played. Sorry folks, this is not the situation that Law 57D deals with, this is still covered by 45C1. 45C1 says that, unless West has actually shown the ♠2, he can correct this. (If the ♠2 was shown, it becomes a penalty card, to be dealt with as before).
I don’t know how Law 57D was introduced to some players, but it looks as if it took nature needed 23 days to invent an idiot capable of abusing it.
Of course, if you find a specimen of such an idiot, feel free to point him to this blog.