[shevek]

With West dealer, the bidding goes

1♥ - (2♠) - 2♦

When the smoke clears, East decides to change his call to 4♥.
Then we get


1♥ - (2♠) - 4♥ - (4♠)
All pass.

East leads a heart to his partner's ♥A.

As I read 26B, North can say to West "Don't lead a CLUB."
Seems strange to me. How did clubs get involved?

[gordontd]

shevek, on 2020-January-28, 19:52, said:

How did clubs get involved?

By not being specified in the legal auction.

[barmar]

gordontd, on 2020-January-29, 01:19, said:

By not being specified in the legal auction.

That's obvious. I think shevek may be wondering about the rationale for this.

I think the idea is that leading a suit that partner bid legally doesn't take advantage of the irregularity in any way, so declarer shouldn't be able to prohibit it. So we give declarer the option of prohibiting any other suits.

In the example auction, declarer might want to prohibit a diamond lead. This is allowed because the withdrawn call is not part of the legal auction. But if he finds it more useful to prohibit a club, he can do that as well. The only thing he can't do is prohibit a heart, since East's heart bid was legal.

[pescetom]

barmar, on 2020-January-29, 09:00, said:

The only thing he can't do is prohibit a heart, since East's heart bid was legal.

Another thing he can't do is to require a heart. But he can (as I read it) prohibit or require any other one suit, be that diamonds, clubs or his own spades. So he can force West to lead a trump, having AQT in the dummy, for instance.

[RMB1]

pescetom, on 2020-January-29, 11:48, said:

Another thing he can't do is to require a heart. But he can (as I read it) prohibit or require any other one suit, be that diamonds, clubs or his own spades. So he can force West to lead a trump, having AQT in the dummy, for instance.

Not 'require'. Law 26B was edited, as follows:

When an offending player’s call is withdrawn and it is not replaced by a comparable call, then if he becomes a defender declarer may, at the offender’s partner’s first turn to lead (which may be the opening lead) either:
1. require the offender’s partner to lead any (one) suit which has not been specified in the legal auction by the offender; or
2. prohibit offender’s partner from leading any (one) suit which has not been specified in the legal auction by the offender. Such prohibition continues for as long as the offender’s partner retains the lead.

[RMB1]

RMB1, on 2020-January-29, 11:59, said:

Not 'require'. Law 26B was edited, as follows:

The OP is named '26B2' - there is no Law 26B2 because there is no Law 26B1.

[pescetom]

RMB1, on 2020-January-29, 11:59, said:

Not 'require'. Law 26B was edited, as follows:

When an offending player’s call is withdrawn and it is not replaced by a comparable call, then if he becomes a defender declarer may, at the offender’s partner’s first turn to lead (which may be the opening lead) either:
1. require the offender’s partner to lead any (one) suit which has not been specified in the legal auction by the offender; or
2. prohibit offender’s partner from leading any (one) suit which has not been specified in the legal auction by the offender. Such prohibition continues for as long as the offender’s partner retains the lead.

Thank you, that was not in my "2017 LAWS OF DUPLICATE BRIDGE" page 31.
I see this note now.
Arguably not good process and an arbitrary change, but important to know nevertheless.

[chrism]

One thing that I find slightly odd about 26B is that as worded, it applies even when the withdrawn denomination had been specified by the offender elsewhere in the auction. For example
(3S) 4C (4S) X;
(P) 4C

Not accepted, Pass substituted, and the auction is now passed out in 4Sx. When offender's partner is first on lead, declarer can still prohibit the lead of a spade, heart or diamond. My understanding is that this was indeed the intent of the lawmakers; I don't understand the rationale (other than simplicity of application).

[pescetom]

chrism, on 2020-February-04, 06:06, said:

One thing that I find slightly odd about 26B is that as worded, it applies even when the withdrawn denomination had been specified by the offender elsewhere in the auction.
...
My understanding is that this was indeed the intent of the lawmakers; I don't understand the rationale (other than simplicity of application).

I agree it's not particularily logical, but then neither is the entire law as it stands. It looks to me as if it originally had some punitive intent and I imagine the lawmakers wished to retain that as a deterrent regardless of whether the withdrawn denomination had already been specified legally or not.

I am more curious to know why in 2017 they decided to draw some teeth from the law by leaving only the option of prohibition. There must have been some strong concern if they felt obliged to modify the new laws immediately after emission in this way.

[gordontd]

pescetom, on 2020-February-04, 07:38, said:

I am more curious to know why in 2017 they decided to draw some teeth from the law by leaving only the option of prohibition. There must have been some strong concern if they felt obliged to modify the new laws immediately after emission in this way.

There was widespread objection among TDs when the laws were first released to them. It was simply felt to be too much.

[pescetom]

gordontd, on 2020-February-04, 08:16, said:

There was widespread objection among TDs when the laws were first released to them. It was simply felt to be too much.

Thanks. I located the 2007 Laws now and can see what happened, they simplified rather brutally. Before 2017 the require/prohibit power was present, but only for a suit that was specified in the withdrawn call but not legally specified previously - if no suit was specified in the withdrawn call then any one suit could be prohibited (but not required) and if the suit specified in the withdrawn call had already been legally specified then there were no lead restrictions at all.

The older law was undoubtedly more complete and balanced, but as an exponent of simpler laws with deterrent effect I can live with the modified 2017 version.

[pran]

chrism, on 2020-February-04, 06:06, said:

One thing that I find slightly odd about 26B is that as worded, it applies even when the withdrawn denomination had been specified by the offender elsewhere in the auction. For example
(3S) 4C (4S) X;
(P) 4C

Not accepted, Pass substituted, and the auction is now passed out in 4Sx. When offender's partner is first on lead, declarer can still prohibit the lead of a spade, heart or diamond. My understanding is that this was indeed the intent of the lawmakers; I don't understand the rationale (other than simplicity of application).

Just to avoid any misunderstanding:
(quote from Law 26B) "Declarer may, at the offender’s partner’s first turn to lead (which may be the opening lead) prohibit offender’s partner from leading any (one) suit which has not been specified in the legal auction by the offender".

Declarer may not specify more than one such suit.

[barmar]

chrism, on 2020-February-04, 06:06, said:

I don't understand the rationale (other than simplicity of application).

I think my summary of the rationale encompasses it.

Suppose a player makes a bid that has lead direction implications. If they previously or subsequently make an illegal bid that has to be withdrawn, we don't want to give declarer the ability to prohibit that lead -- it seems too punitive.

[weejonnie]

Having part 1 would probably be against the spirit of trying to get as normal a bridge result as possible as the offender's partner couldl be compelled to concede a trick e.g. leading into a tenance, in a suit totally unrelated to the UI given by the withdrawn call.

Part 2 is a bit wider than a simple correction - which presumably would be to "forbid the offender's partner from leading one or more suits specified by the illegal bid".

[pran]

weejonnie, on 2020-February-08, 18:01, said:

Having part 1 would probably be against the spirit of trying to get as normal a bridge result as possible as the offender's partner couldl be compelled to concede a trick e.g. leading into a tenance, in a suit totally unrelated to the UI given by the withdrawn call.

Part 2 is a bit wider than a simple correction - which presumably would be to "forbid the offender's partner from leading one or more suits specified by the illegal bid".

It never was - have you overlooked:

pran, on 2020-February-04, 10:38, said:

Just to avoid any misunderstanding:
(quote from Law 26B) "Declarer may, at the offender’s partner’s first turn to lead (which may be the opening lead) prohibit offender’s partner from leading any (one) suit which has not been specified in the legal auction by the offender".

Declarer may not specify more than one such suit.

???

[mycroft]

The old law was much trickier to rule, which I think was one of the reasons for the change. 1♠-(3♦)-3♦, anyone? What suits declarer was able to require or forbid depended on what the IB was intending to do, and there was the "did it show a suit or suits or not?" question.

They first went to "require or forbid any one suit not specified", but found that to be over-beneficial to declarer. So they went to simply allowing declarer to bar any one suit not specified. Much easier to resolve as TD, much easier to understand as declarer, perhaps more beneficial to declarer than pre-2017, but not overly so.