variable NT range

[Shugart23]

Can I open a variable 1NT whish shows either 10-13 HCP and denies a 4 card Heart suit OR shows 13-15 HCP and promises a 4 card Heart suit, under ACBL rules ? I suspect not, but seek clarification. Thank you

[barmar]

You can open it, but you might not be allowed to use conventional responses and rebids after it. Under GCC Responses and Rebids:

10. ALL CALLS AFTER A NATURAL NOTRUMP opening bid or direct

overcall, EXCEPT for natural notrump opening bids or overcalls with a lower

limit of fewer than 10 HCP or with a range of greater than 5 HCP (including

those that have two non-consecutive ranges).

 

I'm not sure we've ever gotten clarification on how "range greater than 5 HCP" is to be calculated -- is it high-low, or is it the number of items in the range? By the first definition your range fits, but since your range contains 10, 11, 12, 13, 14, 15, which is 6, it would be excluded under the second.

 

As far as I can tell, the part about promising and denying 4 hearts has no impact, as long as the hand is balanced.

[wank]

i don't speak acbl, but 10-15 is a 5 point range in any normal parlance.

[Cyberyeti]

i don't speak acbl, but 10-15 is a 5 point range in any normal parlance.

 

This is used inconsitently, don't know what ACBL means, but some say 10, 11, 12, 13, 14, 15 is a 6 point range.

[WellSpyder]

i don't speak acbl, but 10-15 is a 5 point range in any normal parlance.

I'm sure others have been round the houses on this before, but I'm not sure I agree. I certainly think of 12-14 as a 3-point range. And indeed when discussing NT ladders with at least one partner we have discussed whether it makes a significant difference to devise a ladder based on 2-point or 3-point ranges for stronger hands, eg whether you should be able to show 21-2 points with a 2N opening rather than 20-22. On that basis, 10-15 is a 6 point range.

[Shugart23]

well, I am in the camp that 10-15 is a 6 point range.......Now I am curious about a similar question, not that I am thinking of doing this...but are you allowed to have 1NT be 10-11 OR 20-21 ? Is that a pair of two point ranges which totals to 4, or is that a 12 point range.

 

Here, I assume you are allowed to do this, but I am more interested if you could use conventions afterwards, if adopting such a scheme....

[jeffford76]

well, I am in the camp that 10-15 is a 6 point range.......Now I am curious about a similar question, not that I am thinking of doing this...but are you allowed to have 1NT be 10-11 OR 20-21 ? Is that a pair of two point ranges which totals to 4, or is that a 12 point range.

 

Here, I assume you are allowed to do this, but I am more interested if you could use conventions afterwards, if adopting such a scheme....

 

The part on the GCC about "including those that have non-consecutive ranges" means that for this purpose your range is 10-21, a 12 point range (not 11), so conventions would not be allowed.

[aguahombre]

Variable nt means it varies according to position or colors. Your questions are about 1) a wide range and then 2) about a non-touching split range. The span of 10 through 15 is six.

[johnu]

i don't speak acbl, but 10-15 is a 5 point range in any normal parlance.

 

As a mathematical definition, you are 100% correct, however few have accused the ACBL convention charts of being "normal". I think the ACBL convention charts which are very poorly written and need to be rewritten by a bridge-savvy tech writer uses one of the secondary meanings of range, e.g. a set of different things of the same general type.

 

This could be cleared up if the convention chart gave an example of a 5 point range so anybody reading the chart would know for sure.

[kenrexford]

I was involved in a prior discussion as to this. I find the idea of a heart anchor or lack thereof as the clue to range as fascinating. That said, I also find this to bring up a silly GCC issue.

 

I think 10-12 or 14-16 is OK, because each range is less than 5. It would be weird to require non-consecutive ranges, if that is right. It might mean, however, that 10-12 is OK only if coupled with 15-16, as the net range is 5 options.

 

As a lawyer, I would argue that 10-12 and 13-15 are non-consecutive ranges BECAUSE one promises hearts and the other denies hearts. That renders the nature of each "range" unique.

 

I am curious about the unwind and think that 2NT as a rebid shows some range with spades only?

 

 

 

[Vampyr]

As a mathematical definition, you are 100% correct, however few have accused the ACBL convention charts of being "normal". I think the ACBL convention charts which are very poorly written and need to be rewritten by a bridge-savvy tech writer uses one of the secondary meanings of range, e.g. a set of different things of the same general type.

 

This could be cleared up if the convention chart gave an example of a 5 point range so anybody reading the chart would know for sure.

 

Perhaps the ACBL convention charts are poorly written, but not in this instance. 10, 11, 12, 13, 14, 15 ... count'em, six.

[RMB1]

As a mathematical definition, you are 100% correct,

 

In mathematics, a range is set, not a number. When we assign a number to a range it is its size or length. If HCP are real numbers, then the range "10-15" is the interval [10.0, 15.0] which has length 5.0. If HCP are whole numbers, then the range "10-15" is the set {10, 11, 12, 13, 14, 15}; this set does not have a length but it has size (cardinality) 6.

[johnu]

Perhaps the ACBL convention charts are poorly written, but not in this instance. 10, 11, 12, 13, 14, 15 ... count'em, six.

 

There are a huge number of places where range is defined as it pertains to the math world.

 

e.g. http://www.mathgoodies.com/lessons/vol8/range.html#

 

"The range of a set of data is the difference between the highest and lowest values in the set."

 

So the range of 10, 11, 12, 13, 14, 15 is 15 - 10 = 5.

 

If the ACBL wants to use a secondary definition of range to come up with 6 as the answer, then it should give an example so there are no understandings.

[johnu]

In mathematics, a range is set, not a number. When we assign a number to a range it is its size or length. If HCP are real numbers, then the range "10-15" is the interval [10.0, 15.0] which has length 5.0. If HCP are whole numbers, then the range "10-15" is the set {10, 11, 12, 13, 14, 15}; this set does not have a length but it has size (cardinality) 6.

.

 

Look up the definition of range as it pertains to math to see where you are wrong.

[johnu]

I was involved in a prior discussion as to this. I find the idea of a heart anchor or lack thereof as the clue to range as fascinating. That said, I also find this to bring up a silly GCC issue.

 

I think 10-12 or 14-16 is OK, because each range is less than 5. It would be weird to require non-consecutive ranges, if that is right. It might mean, however, that 10-12 is OK only if coupled with 15-16, as the net range is 5 options.

 

As a lawyer, I would argue that 10-12 and 13-15 are non-consecutive ranges BECAUSE one promises hearts and the other denies hearts. That renders the nature of each "range" unique.

 

I am curious about the unwind and think that 2NT as a rebid shows some range with spades only?

 

As a member of a jury, I would agree with the other lawyer :P

[aguahombre]

This is silly. If we are referring to minimum-to-maximum, not including the high number the mathematical pedants can claim 10-15 doesn't include 15 and the span is 5. There is nothing unclear about the span of 10-15 meaning ten through 15.

 

Find something to bash the ACBL about which is actually a problem.

[blackshoe]

In mathematics, a range is set, not a number. When we assign a number to a range it is its size or length. If HCP are real numbers, then the range "10-15" is the interval [10.0, 15.0] which has length 5.0. If HCP are whole numbers, then the range "10-15" is the set {10, 11, 12, 13, 14, 15}; this set does not have a length but it has size (cardinality) 6.

If the ACBL used the word "cardinality" in a regulation, bridge players would pay even less attention to it than they do now.

[sfi]

Can I open a variable 1NT whish shows either 10-13 HCP and denies a 4 card Heart suit OR shows 13-15 HCP and promises a 4 card Heart suit, under ACBL rules ? I suspect not, but seek clarification.

 

Surely the "discussion" about the size of the 10-15 NT range is not relevant here. This use of 1NT is conventional and only allowed at the Superchart level, is it not?

[johnu]

This is silly. If we are referring to minimum-to-maximum, not including the high number the mathematical pedants can claim 10-15 doesn't include 15 and the span is 5. There is nothing unclear about the span of 10-15 meaning ten through 15.

 

Find something to bash the ACBL about which is actually a problem.

 

Well, for one thing the convention charts refer to "range", not span. Span doesn't have the precise meaning that range has, but in this context would have been better to use (along with an example).

[aguahombre]

Well, for one thing the convention charts refer to "range", not span. Span doesn't have the precise meaning that range has, but in this context would have been better to use (along with an example).

Ok. Bring it on; announce 15-17, which obviously means you open 15 or 16 only. Then please explain how the misinformation is mathematically correct, and it is the ACBL's fault for the confusion.

[johnu]

Ok. Bring it on; announce 15-17, which obviously means you open 15 or 16 only. Then please explain how the misinformation is mathematically correct, and it is the ACBL's fault for the confusion.

 

You announce 15 to 17. In what country does this mean 15 or 16? Everybody I know would correctly interpret this as 15, 16 or 17. I suggest you google "range" and clear up you confusion.

[sfi]

You announce 15 to 17. In what country does this mean 15 or 16? Everybody I know would correctly interpret this as 15, 16 or 17. I suggest you google "range" and clear up you confusion.

 

We get it - English is not as precise as mathematical terminology. Nonetheless, everyone else seems to understand the meaning of range in this context with no difficulty. The regulations may be easier to navigate if you don't try so hard to misconstrue their intent.

[johnu]

We get it - English is not as precise as mathematical terminology. Nonetheless, everyone else seems to understand the meaning of range in this context with no difficulty. The regulations may be easier to navigate if you don't try so hard to misconstrue their intent.

 

Everyone else is a huge overbid and the question about range seems to come up fairly frequently so there apparently is some difficulty in divining the intent of the chart drafters.

[aguahombre]

You announce 15 to 17. In what country does this mean 15 or 16? Everybody I know would correctly interpret this as 15, 16 or 17. I suggest you google "range" and clear up you confusion.

Make up your mind; yes, it is a 3 point range. You argue that 10-15 is a five point range in your language of math, then decide it is different when I point out the absurdity of 15-17 being a 2-point range.

[helene_t]

It is true that 15.000 - 10.000 = 5.000 but that is completely irrelevant.

 

If we consider point counts to be discrete then Card{10,11,12,13,14,15}=6.

 

If we consider point counts to be rounded-off numbers based on an underlying continous scale then 15.5-9.5=6.0

 

If 10-12 and 13-15 are considered adjacent intervals then for any measure (call it "cardinality", "length" or whatever you like) it should apply that the size of the 10-15 interval equals the sum of the sizes of 10-12 and 13-15. Claiming that 10-12 and 13-15 are both 2-point ranges while 10-15 is a 5 point range is equivalent to 2+2=5.

 

I don't think ACBL needs to explain the obvious. There may be hundreds of unclear points in ACBL's official documents but this is not one of them.