[andych]

As far as I know, for norwaigen openings

Quote

5 card spades, 4 card red, 3 card club. (5443)
Open the higher of long suits of equal length: 5-5 or 6-6.
Open lower of 4-4. Normally open 1C with 4-4 in the minors.
1C is only 3 card if 4 spades - 333. (Some also opens 1C with 3433)
1H is only 4 card if 3433, 4432 or 4423.

Anyone has a dealer program to tell
1) the % of time 1♥ opening is only 4 card?
2) the % of time 1♣ opening is only 3 card?

[FrancesHinden]

Depends on the NT opening range, and whether you can open 1NT with a 5-card major, and (very slightly) how strong you can be with, say, a 5431 before you don't open it 1H.

By the way, you don't need a dealer program to answer this question.

1. If you never open 1NT, then a 1H opening is 4 cards when exactly 4=4 in the majors (and 2-3 in the minors) or 3=4=3=3 with 12-19 HCP, or 2.1% of the time

2. A 5+ heart opening is any hand with 6+ hearts and fewer spades and, say, 10-20 HCP plus any hand with 5 hearts and not five spades and, say, 11-20 HCP, but not 5332 20-counts which is, I think, 7.6% of the time.

So a 5+ card heart suit is roughly 3.5x as common as a 4 card suit. But then you also need to remove the 44(23) and 4333 hands which open 1NT. If that's a 15-17 1NT opening, a 4-card heart suit reduces to 1.44% of the time. If it's a 12-14 1NT opening, a 4-card heart suit reduces to 0.81% of the time

If you open 1C on all 4=4 in the minors, and it only has 3 when precisely 4=3=3=3 you can basically forget about a 1C opening being 3, it's extraordinarily rare compared to a 4+ club. Even more so if you play weak NT.

[hotShot]

[Edit: Assuming they don't open NT since no range is given, % is from all deals]

1) 1♥ ~ 2.2% for 12+ HCP and shape in {3433, 4432, 4423}
2) 1♣ ~ 4.7% for 12+ HCP and shape in {4333, 2344, 3244, 3424, 2434, 4234 , 4324}
~5.3% 12+HCP and 5+ cards and ♣ is longest suit
~ 0.9% for 12+ HCP and shape in 4333 (~0.63% removing the 15-17 HCP range)

Without removing the NT hands from the other shapes (that will increase the percentage of 3 card ♣) it is about 6-7%.

[Walddk]

FrancesHinden, on Nov 12 2008, 03:09 PM, said:

Depends on the NT opening range

Standard in Norway is 15-17. Norwegian Standard is also Danish Standard (5 spades, 4 hearts). The chance that 1♣ is only three cards (4333) is roughly 5%. 3343 is opened 1♦, not 1♣.

Students are taught to treat 1♣ as 4+ and support accordingly.

Don't know about 1♥ being only 4 (3433, 4432, 4423). Some mathematician will likely calculate it for us.

Roland

[FrancesHinden]

hotShot, on Nov 12 2008, 01:22 PM, said:

[Edit: Assuming they don't open NT since no range is given, % is from all deals]

1) 1♥ ~ 2.2% for 12+ HCP and shape in {3433, 4432, 4423}
2) 1♣ ~ 2.2% for 12+ HCP and shape in {4333, 2344, 3244}
~ 0.9% for 12+ HCP and shape in 4333
But wouldn't 3424, 2434, 4234 or 4324 shapes be opened 1♣ too?

2) you've missed out all the 5+ card club suits that also open 1C

[FrancesHinden]

Ignoring point count constraints, a club is 3 cards only on 2.6% of all shapes, and is 4+ cards on 31% of all shapes. Once you remove the 1NT openers you see how unlikely a short club becomes.

[hotShot]

FrancesHinden, on Nov 12 2008, 03:33 PM, said:

2) you've missed out all the 5+ card club suits that also open 1C

Of cause you're right, I will add them later.

[andych]

hotShot, on Nov 12 2008, 01:22 PM, said:

[Edit: Assuming they don't open NT since no range is given, % is from all deals]

1) 1♥ ~ 2.2% for 12+ HCP and shape in {3433, 4432, 4423}
2) 1♣ ~ 4.7% for 12+ HCP and shape in {4333, 2344, 3244, 3424, 2434,  4234 , 4324} 
             ~5.3% 12+HCP and 5+ cards and ♣ is longest suit
             ~ 0.9% for 12+ HCP and shape in 4333 (~0.63% removing the 15-17 HCP range)

Without removing the NT hands from the other shapes (that will increase the percentage of 3 card ♣) it is about 6-7%.

Thanks for the figures. 3424, 2434, 4234 or 4324 hands are opened 1♣ as I know. Opener lower of 44.
Assume 1NT is 15-17 with 5cM allowed. For simplicity assume all 20+ hands are opened 2♣/2NT/etc.

May I know the following?

A % of hands are PASS.
B % of hands opens 1♣. Within these B%, B1% hands with only 3 cards.
C% of hands opens 1♦
D % of hands opens 1♥. Within these D%, D1% hands with only 4 cards.
E% of hands opens 1♠



My wild guess ...
30 % of hands are PASS.
20 % of hands opens 1♣. Within these 20%, 5% hands with only 3 cards.
20 % of hands opens 1♦
10 % of hands opens 1♥. Within these 10%, 8% hands with only 4 cards.
10% of hands opens 1♠


The other 10% hands are 2♣/1NT/2NT/weak 2 openings.

Like to know how poor is my guess

Thanks

[hotShot]

andych, on Nov 12 2008, 05:02 PM, said:

A % of hands are PASS.
B % of hands opens 1♣. Within these B%, B1% hands with only 3 cards.
C% of hands opens 1♦
D % of hands opens 1♥. Within these D%, D1% hands with only 4 cards.
E% of hands opens 1♠

If you allow 1NT to have 5cM, there is no simple way to decide what to open with a 5cM hand. So I will ignore that. I assume that 12 HCP is the minimum opening strength, there is no strong bid to set an upper limit to the HCP.

If you take the rule of 18 as a general definition for an opening (and you don't want to open a lot of them) about 55-60% of all deals an opener gets, are a PASS.

8.6% of all deals are 1♣ openings (not allowing 5cm's in NT)
0.63% of all deals are a 1♣ opening and contain only 3 ♣.
=> ~7.3% of the 1♣ openings have only 3♣.

6.8% of all deals have ♥ as longest suit (5+) or the shape is {3433, 4432, 4423} (15-17HCP excluded)
1.6% of all deals have the shape {3433, 4432, 4423} (15-17HCP excluded)
=> 23.5% of the 1♥ openings show a 4 card suit

[andych]

hotShot, on Nov 12 2008, 04:07 PM, said:

andych, on Nov 12 2008, 05:02 PM, said:

A % of hands are PASS.
B % of hands opens 1♣.  Within these B%, B1% hands with only 3 cards.
C% of hands opens 1♦
D % of hands opens 1♥.  Within these D%, D1% hands with only 4 cards.
E% of hands opens 1♠

If you allow 1NT to have 5cM, there is no simple way to decide what to open with a 5cM hand. So I will ignore that. I assume that 12 HCP is the minimum opening strength, there is no strong bid to set an upper limit to the HCP.

If you take the rule of 18 as a general definition for an opening (and you don't want to open a lot of them) about 55-60% of all deals an opener gets, are a PASS.

8.6% of all deals are 1♣ openings (not allowing 5cm's in NT)
0.63% of all deals are a 1♣ opening and contain only 3 ♣.
=> ~7.3% of the 1♣ openings have only 3♣.

6.8% of all deals have ♥ as longest suit (5+) or the shape is {3433, 4432, 4423} (15-17HCP excluded)
1.6% of all deals have the shape {3433, 4432, 4423} (15-17HCP excluded)
=> 23.5% of the 1♥ openings show a 4 card suit

Thank you very much hotShot

My guess on 1♥ opening with 4 cards is so poor.

BTW also have to thank FrancisHinden, and who is so close to 23.5% ... amazing...

Quote

So a 5+ card heart suit is roughly 3.5x as common as a 4 card suit.

[NickRW]

I'm not sure I understand the design logic of this. 1H is mostly 5 if you open 4H4m with 1m - yet it doesn't guarantee 5. Conversely, the 1H opening, only showing 4, is not put to maximum use when you open 4H4m with 1m.

Basically what I am saying is that I understand 5 card majors (preferably 5542 rather than 5533 to my mind - but the difference is minor). And I understand true 4 card majors (i.e. not bidding 4 carders up the line except 44 majors). And I understand 5 card spades with true 4 card hearts. And have played them all. But I don't really understand what the point of playing 4 card hearts is and then not using it to the max is.

Perhaps one of our Nordic friends can explain the "why" rather than the "what" of this opening strategy please.

Nick

[helene_t]

They teach something similar to beginners in the Netherlands.

One of the sales points is that
1♥-1♠
1NT-2♥
finds a 5-3 fit because responder knows that opener has 5 hearts since he didn't support spades. And 1♣ really promises 3 while 1♦ really promises 4!

Edit: Roland's point below is a better case.

More seriously, I think it evolved as a compromise aimed at avoiding that the country got split in a civil war between the 4-card-majorites and the 5-card-majorites. By playing a system that combines the disadvantages of 4-card majors with the disadvantages of 5-card majors, both sides are comforted by the fact that the enemy didn't get their pick either.

[Walddk]

NickRW, on Nov 12 2008, 07:05 PM, said:

Perhaps one of our Nordic friends can explain the "why" rather than the "what" of this opening strategy please.

The idea behind opening 4-card suits up the line is that you will discover any fit, major as well as minor. That is not always the case if you open 1M.

1♥ - 2♣
3♣

I can't live with the raise if it doesn't also show five hearts. And if you claim that it does and you can just rebid 2NT with 4-4 in hearts and clubs, then I can't accept that either. Why conceal that you have support for partner's suit, even though it's a minor?

3♣ might make her hand so much better.

Roland

[NickRW]

Thank you, both Helene & Roland.

Walddk, on Nov 12 2008, 05:28 PM, said:

I can't live with the raise if it doesn't also show five hearts. And if you claim that it does and you can just rebid 2NT with 4-4 in hearts and clubs, then I can't accept that either. Why conceal that you have support for partner's suit, even though it's a minor?

Because you play MP and want to score 120 instead of 110? Perhaps I play too much MP!

Nick

[skjaeran]

The standard 1NT range is more like 14.6-16.8, since very many quite freely upgrades 14-counts.

Originally, the standard in Norway was to open 4-card suits up the line. That meant that 1♠ would provide a 5-bagger about 95% of the time. In the mid 70s, the standard started switching to guarantee 5 when opening 1♠ to more freely be able to support with only three.