2017 Laws Commentary - Example 36 - help required.
I've been working me way through the commentary, and I don't understand example 36:
Law 31B - With Partner or LHO to Call
Partner is initially restricted by UI and for the offender, the same approach as in A applies.
Example 36 (Dealer W):
W N E S
- - 1♣ (could be short, not accepted)
1♠ X ?
XX showing10+ HCP is a comparable call;
Why? Surely the 1C COOT shows clubs whereas the redouble does not (necessarily) show clubs? It's certainly not a subset of the possible meanings attributable to the withdrawn call, so they must be saying the meaning is sufficiently similar.
Is that so? If so, when does information about a suit make it sufficiently different?
Comments
Well, I suppose the implied short spades means probable club length, which isn't considered a million miles away from your average 3/4 card club opener. I'm not sure if I agree with the example myself, but I can see it as a possibility.
My guess is that the example assumes the old-fashioned style whereby all strong (10+) hands redouble first, regardless of strength.
The commentary on law 23 is, in part
"The concept is broadened to say that a call replacing another normally does not create harmful
information if it is more precise.The application of this concept means that after such a call the auction may continue normally without damaging the other side. In this approach the emphasis is more on the suits shown than on the strength. If however the strength differs too much then the calls cannot be considered comparable."
Of course I am not sure how "too much" is defined. But since the XX is showing a hand close to or exceeding an opening bid and doesn't really say anything about clubs then under this commentary it would be OK. NB TD shopuld of course check that the XX does, in fact show this.
But surely a redouble showing 10+ is less precise than a 1 !c opening. The example seems to concentrate on the similar strength and ignore the suits (potentially) shown, which seems to contradict the general statement quoted.
If they mean that it is comparable only because the 1 !c opening was potentially short, it would have been helpful had they said so.
Do people agree that if the 1 !c had shown 4+ cards (particularly in a 4-card major style where balanced hands with a major outside the NT range are opened 1M, so 1m is more likely to be 5+ than in other styles), then the redouble would not be a comparable call, given that it is demonstrably less precise and does not comply with the principle of emphasis on suits shown?
I think this can only be comparable in a five-card major system. In a four-card system, 1!c denies hearts, XX does not deny them (in fact, it somewhat tends to suggest holding them). If the opener actually holds hearts in addition to spades, then they have useful UI from the 1!c call (that, say, could warn them from pulling the redouble to 2!h), and thus I'd hesitate to consider XX comparable; that's normally used in cases where the UI from the withdrawn bid is not usable.
In a five-card major system, the fact that 1!c denies five hearts and XX doesn't might reasonably be considered unimportant enough that XX can be considered comparable (likewise, that 1!c shows 2 or 3 clubs depending on system, and XX doesn't guarantee them; that's less of a factor than with the hearts).
How so?
If 1 !c shows 4+ clubs (or even 3) then a XX would not be comparable unless it guaranteed some length in clubs. This is not impossible, of course, when you think about it since usually the XX denied support for the suit bid. However I bet that very few players would actually take the trouble to limit/ describe their XXs as such.
Oh right, 4 clubs and 4 hearts is a possible holding in some systems, and 5 clubs and 4 hearts is in most. For some reason I was thinking that a hand with hearts would open 1!h instead.
Exactly what I thought. This isn't a "real" situation but an example from the WBFLC commentary, so I expect it to be right, but it still seems that it flies in the face of what comparable call means (at least as far as I understand it).
I really would like to understand why the commentary suggests this is a comparable call, despite the informtion about the club suit.
The only information about the club suit in the given example is that the player holds at least two of them, assuming that is what is meant by "could be short". I would expect that in distributional terms of a hand redoubling, though I would not expect opening values (as a minimum).
I don't know much about systems in which club openings are potentially short. How likely is the club suit to actually be less than 4? If it's (say) 75% of the time then I can see that the double would be comparable, where if (at the other extreme) it was only 25%, then that seems like additional information.
It might be if W is short in clubs, and is looking for 3NT. Plus, law 23 makes no reference to whether or not the information is useful.
The information is that the player has at least two clubs. Not any help for looking for 3NT with short clubs. No, Law 23 doesn't mention the usefulness of the information, but this will affect the likelihood of needing to make a Law 23C adjustment afterwards.
Understood.
I think I'm there now. Thanks @gordonrainsford and others.
I don't think that just because a redouble denies support for the suit opened it can necessarily be taken to imply length in another suit (here, clubs). Of course the expected* number of clubs in a hand is more with a known shortage in the suit opened than without, but the redouble doesn't actually show any length in clubs.
*(using "expected" in the statistical sense, not in the sense of expected from the systemic agreements).
With most partners my redouble would indeed specifically deny support and would be explained as such, but I am sure that Gordon is right in an earlier post that the way the example is worded assumes an old-fashioned 10+ without other constraints
Okay, with one of my partners I play 1C as 11+ points with no 5 card major and could have longer diamonds (1D is either a 5 card suit, or 4441 with singleton club).
A redouble for me is old fashioned, 10+ points, no 5 card major, does not deny support and can be just about any shape.
So I can see here that 1C open = 11+ points, no 5 card major
redouble = 10+ points, no 5 card major
Similar meaning as only 1 point difference and very little additional information passed. I suspect that is it this type of bidding system that they mean, so that the redouble is quite close to a 1C open?
There is s similar discussion on BBO https://www.bridgebase.com/forums/topic/79998-comparable-call/ disussing a 1 !c BOOT and a 2NT replacement call at the correct time. My argument is since the 1 !c opening bid COULD show a pretty strong balanced hand then 2NT is comparable - as the meaning of 2NT is one attributable to the 1 !c call.
One thing to consider is not necessarily the club length itself when it "could be short", but you know the player won't be holding more diamonds than clubs after a withdrawn 1C opening, information that his partner is not allowed to have. In the case of 1S-Double-Redouble, responder might hold xx AJx KQxxx Jxx, but opener is going to know that hand or a similar hand with longer diamonds than clubs will not be held after the withdrawn 1C opening.
Some might say this would infrequently matter, and often a very liberal allowance of redouble as being comparable will work out OK for the Director. If the offending side ends on defense, the information about lack of diamond length may be important (and you can't directly use the UI law which does not apply after you considered redouble to be comparable), so the Director will need to be on his toes with regards to potential adjustment under Law 23C.
It is of course not unheard-of for players playing a 2+ 1 !c opening to agree to open 1 !c with four diamonds and two or three clubs in a balanced hand, in which case the inference about longer diamonds would not apply.
23A2 seems to cover the situation though where a call MIGHT have 5 hearts and the replacement call denies it.
...
Since I assume the 1st definition would be "16-18 MIGHT have 5 hearts" can be split into two subsets
"16 - 18 : has 5 hearts" and
"16 - 18 : does not have 5 hearts"