[32519]

Big ♣ systems open 1♣ to show 16+ HCP.
Big ♦ systems do the same.
Then you have Gazzilli which uses an artificial 2♣ over 1M-1NT to show extras.
Serious / Non-Serious 3NT in a 2/1 auction also tends to show 16+.
A normal reverse bid also shows 16+ HCP.

So why was 16 HCP chosen as the magical number? Just curious!

[helene_t]

You need to open with 12 points since otherwise the risk of a board belonging to us being passes out is too big.

12-15 is a manageable range for a precision 1nt or 2cl opening, or s standard 1nt or 2m rebid. It still gives responder the room to make a limit bid (2NT) catering to a maximum without being ridicolously high opposite a minimum.

Hence with 16+ you need to do something else. A 1M opening in a strong-club system, or non-reverse shift by opener, can have a wider range if you want.

[hrothgar]

32519, on 2012-May-10, 04:27, said:

Big ♣ systems open 1♣ to show 16+ HCP.
Big ♦ systems do the same.
Then you have Gazzilli which uses an artificial 2♣ over 1M-1NT to show extras.
Serious / Non-Serious 3NT in a 2/1 auction also tends to show 16+.
A normal reverse bid also shows 16+ HCP.

So why was 16 HCP chosen as the magical number? Just curious!

There's nothing magic about 16 HCP (or, for that matter, HCPs)

Strong club openings used to show much stronger hands (Think Blue Club, Schenken, etc...)
Today many strong club openings show weaker hands (think MOSCITO and the like)

[the hog]

32519, on 2012-May-10, 04:27, said:

Big ♣ systems open 1♣ to show 16+ HCP.
Big ♦ systems do the same.
Then you have Gazzilli which uses an artificial 2♣ over 1M-1NT to show extras.
Serious / Non-Serious 3NT in a 2/1 auction also tends to show 16+.
A normal reverse bid also shows 16+ HCP.

So why was 16 HCP chosen as the magical number? Just curious!

16 is an Ace more than a min opening.

[ArtK78]

Prior to the introduction of Precision in the early 1970s, the magic number was 17. The various big club systems of the day (Blue Team, Schenken, etc.) used 17 as the minimum for opening 1♣. In the introduction to the original Precision book, it was stated that the minimum for opening a strong club was lowered to 16 so that many more hands would be opened with 1♣.

So, there really is nothing magical about the number 16. It is just the way systems have evolved over time.

[Zelandakh]

The history of this is that 10-12 was regarded as invitational range, so a weaker hand has a max of 9. Since Opener has a max of 19 (back in the days of Strong Twos) 6 was chosen as the minimum for the weak range, ie 6-9. 16 is therefore the point at which you want to invite over this range. In fact some earlier texts talk more about 17 points, or perhaps a good 16. That gave Opener ranges of 13-16/17-18/19. Since you can invite over the weak range you ended up with 13-14/15-16/17-18/19 - perfect, no? Nowadays the ranges would be more like 10-12/13-15/16-17/18-19. Nonetheless I hope you can see that 16 makes more sense when you do not require "13 to open".

Similarly the requirement for reverses was traditionally 17+, at least in America. Some still play "strong reverses". The range of 16 for reverses came (I think) from Acol, where opening light was the norm. When you open lighter you need to extend the ranges a little bit as above. You also mention the value for Serious 3NT to be 16+. I have never heard this. When you are looking at slams your controls and placement of honours are at least as important as raw points. Serious means to me a hand that wants to be in slam opposite controls in all side suits and 4+ key cards. If Serious to you means a slam try then I still think you are wrong but at least I understand some context.

Why 16 was required for Precision is a question I have no real idea about. My guess would be that it was chosen so that no strong rebids from Standard were required. That allowed the Precision jumps without being seen to give up anything. As has been pointed out, other strong club systems have used different ranges. Notice that the value 16 does not appear anywhere as a boundary range for the opening of my (strong club) system but it is still the (approximate) boundary for a strong rebid opposite a weak response. As soon as you use a 6-9 range somewhere this is practically unavoidable.

And that is the point isn't it? The ranges within a system define the important boundary points for your partner. The traditional ranges for Responder are 6-9(10)/(10)11-12/13-15/16+. This stems directly from the invitational range over an opening bid. If an opening bid were 8-14 then you get a completely different set of ranges for Responder. Sticking with the traditional ranges a moment you can see (as in paragraph one) that we need to show extras with 16ish to invite game over the weak responding range. This gives the reasonable 10-12/13-15/16-17/18-19 ranges that I suggested before, or, if you do not open so light, perhaps 12-13/14-15/16-17/18-19. If Responder shows the stronger range, 13+, then we usually only have space to show 3 ranges - minimum, extras and slammy. If we say the last of these is something like 19+ and we split the rest down the middle we end up with something like 13-15/16-18/19+, assuming that distributional features will bring Opener's hand up to being worth a solid opening. But then, perhaps we can get a fourth range in there for total rubbish by jumping to game - call that 10-12 including distribution, whatever.

Anyway, perhaps this is what you mean by Serious 3NT being 16+. You would not really want it to be less than this or your ranges get too large to make sensible decisions. If you are genuinely interested in this kind of question then you should really get down into the nuts and bolts of a bidding system and see how the different ranges for a particular hand type work out. In doing this you can see immediately why the ranges are as they are. The ranges in my system are (for ♦, ♥ and ♠) usually 10-13/14-17/18-20/"Acol 2"/GF. That is because I accept an invite with 14 and this splits the hand values up nicely. Therefore an invitational hand has to be willing to play game opposite 14. However, as I said above, when Responder is weak the ranges switch to 10-15/16-17/18-20/"Acol 2"/GF. That is because there is (usually) no game interest with the 10-15 hands. I say usually here because one should always be willing to upgrade well-fitting hands. As with the discussion about serious slam interest, there are sometimes more important factors than simply counting points.

In summary, 16 is not a magic number. It is simply a logical boundary point in a number of systems.

[Vampyr]

ArtK78, on 2012-May-10, 05:30, said:

In the introduction to the original Precision book, it was stated that the minimum for opening a strong club was lowered to 16 so that many more hands would be opened with 1♣.

This seems illogical. Isn't the 1♣ opening the weak point of strong club systems?

[ArtK78]

Vampyr, on 2012-May-10, 06:21, said:

This seems illogical. Isn't the 1♣ opening the weak point of strong club systems?

I agree with you. However, at the time that Precision was introduced to North America, strong club systems had virtually disappeared. So, the fact that the strong club opening was the weak point in the system was not well known. It was assumed by the bridge playing populace that the strong point of a strong club system was the strong club opening.

[ArtK78]

By the way, for those of you who are stating that 12 HCP is a minimum opening, and 12-15 is the range of a minimum opening, and that 16 HCP is one ace better than minimum, keep in mind that for the better part of the 20th century a minimum opening bid was considered to be 13 HCP, so the argument you are making for 16 HCP could be made for 17 HCP.

[blackshoe]

It's a weak point because people have learned to interfere over it on dreck. They didn't do that in the 1970s.

Romex Forcing Club (RFC) is a modern system that uses 17 as the minimum for 1♣. Also, Romex players who play it are either practicing, or using the "two card" system. In the latter case, they only play RFC when not vulnerable (at MPs) or at favorable (at IMPs). That minimizes the opportunity for opponents to come in.

[hrothgar]

ArtK78, on 2012-May-10, 07:29, said:

I agree with you. However, at the time that Precision was introduced to North America, strong club systems had virtually disappeared.

I'd be interested to see some supporting data

My impression is that strong club systems were never particularly popular in North America.

Yes, Vanderbilt developed the first strong club system
Yes, Schenken wrote his book on the "Big" Club

However, I don't think that either system was ever in in widespead use.
(I don't think there was anything to "disappear")

My impression is that there was a spike in interest in strong club systems associated with Wei's efforts to promote Precision.
I suspect that interest in the general public has decreased somewhat

I'm guessing that there is a slight up-tick in strong club use among-st professions, largely spurred by

The success of some well known strong club pairs
The ability of professionals to invest significant time/effort into their partnerships

[barmar]

A related question: Why is 8 the magic number for a positive response? It's a game force, but 16+8 is only 24, which isn't generally considered enough for game unless you have some additional distributional features (or you're Meckwell, who seem to bid game with most 23 counts).

[awm]

The choice of 16 is not universal. I've played against strong club systems that start at 15 or 17. Polish club usually starts at 18 (although it also includes weak notrump). When I play Gazzilli, it normally starts at 17 (and this is right out of the Ambra notes so I didn't make this up out of thin air). While I do start reverses at 16, some very good players start them at 17 (and of course everyone upgrades really extreme shapes).

There are a few reasons that 16 is popular though:

(1) It's about half what you need for slam. This meshes well with openings that are about half what you need for game.
(2) It's the weakest hand where you're likely to have game opposite a partner who is too weak for a normal invite (which starts around 10).
(3) It's the starting point in CC Wei Precision (which most modern strong club methods spun off from).

As for game-forcing with 8 opposite 16, it's the same reason that people game force 9 opposite 15-17 notrump. You want to minimize the invitational sequences, and bidding 24 hcp games (especially at IMPs) is not the end of the world.

[JLOGIC]

barmar, on 2012-May-10, 08:43, said:

A related question: Why is 8 the magic number for a positive response? It's a game force, but 16+8 is only 24, which isn't generally considered enough for game unless you have some additional distributional features (or you're Meckwell, who seem to bid game with most 23 counts).

24=game.

I mean, it's the same thing as bidding 1N p 3N with 9 opp 15-17 which is pretty standard at imps, or making a 2/1 GF with 12 without a fit(many people do that who open 11 counts!). Or, if you open some 10s and all 11s most people will be 2/1 GFing with 13 and no fit.

Or if your partner opens 1D and rebids 1N showing 12-14 don't you bid game with 12?

I think bidding is predicated around being in 24 HCP games as not being bad, and missing it not being horrible. So if your max is 24, you can pass, but if your min is 24 you bid game, and if you are 23-25 you often invite.

[mikeh]

Vampyr, on 2012-May-10, 06:21, said:

This seems illogical. Isn't the 1♣ opening the weak point of strong club systems?

Yes and no: I think that for most pairs, the weakest point is the 2♣ opening, which preempts the opening side in a constructive situation.

As for the 1♣, and it's vulnerability to disruption, I recall reading a BW tournament report in which the author (someone like Cohen or Woolsey, iow a true expert with knowldege) suggested that in his opinion Meckwell did better after interference than they did with an uncontested 1♣ auction (which is pretty damn well anyway).

[bluecalm]

In Polish Club it's 15hcp.
If you open 1S then all the jumps, reverses, 2NT's are 15+.

[hrothgar]

bluecalm, on 2012-May-10, 09:47, said:

In Polish Club it's 15hcp.
If you open 1S then all the jumps, reverses, 2NT's are 15+.

A "classic" Polish club opening includes three discrete hand types

A weak NT (which denies a 5 card major)
A single suited hand with clubs with 15-17 HCP
Strong hands starting at 18 or so HCP

In theory, you could combine the last two hand types and claim that the "strong" hands start at 15, however, the rebids are so different that this seems inaccurate

[bluecalm]

I mean after every other opening than 1C. For example:

1D/1H/1S - 2C

Now reverses, 2N and 3level bids are 15+.
Or:

1H - 1S

Now 2N/3C/3D/3H/3S are 15+ in "classic" polish club.
Same goes for pairs who play full range openings.

Also Gazilli doesn't start at 16, it starts at 15, at least as played by world class pairs and yes it means that usually 15+8 = game for Lauria-Versace, Sementa-Duboin or Bocchi-Madala unless someone downgrade along the way (which doesn't happen too often, unless it never happened on vugraph with 5M-(-3-3-2) shape.
It's true that if it goes:
1S - 1N

now 2D and 2H are up to 15 and 2C starts at 16+ but this is because those are convenient bids. If they have 15 in 5-(3-3-2) shape they bid Gazilli and they end up in 15+8 3NT about every time.

[lowerline]

32519, on 2012-May-10, 04:27, said:

Big ♣ systems open 1♣ to show 16+ HCP.
Big ♦ systems do the same.
Then you have Gazzilli which uses an artificial 2♣ over 1M-1NT to show extras.
Serious / Non-Serious 3NT in a 2/1 auction also tends to show 16+.
A normal reverse bid also shows 16+ HCP.

So why was 16 HCP chosen as the magical number? Just curious!

No magic. One of the benefits of a strong club/diamond system is the limited opening. If the limited opening has more than a 5-6 point range, it looses its advantage.
Basically the same with Gazzilli: a range of more than 6 points is too hard to handle. If it wasn't why would you need this convention?
The minimum of a reverse is different after 1-over-1 or 2-over-1. Slam-interest has to do with how well the hands are fitting, not only with points. So definitely no magic 16 in those cases.

Steven

[mikl_plkcc]

Standard bidding (assume 2♣ 20+):
- 1♥ (12-19)
-- 2♥ (6-9) (18-27 combined)
--- 3♥ (16-17) (22-26 combined)
---- 4♥ (8-9) (24-26 combined)
--- 4♥ (18-19) (24-28 combined)
-- 3♥ (10-11) (22-30 combined)
--- 4♥ (14-19) (24-30 combined)
-- 4♥ (12+) (24+ combined)

In this kind of bidding, the combined total for bidding to 4♥ varies as below:
12+12 (1♥ - 4♥)
13+12 (1♥ - 4♥)
14+10 (1♥ - 3♥ - 4♥)
15+10 (1♥ - 3♥ - 4♥)
16+8 (1♥ - 2♥ - 3♥ - 4♥)
17+8 (1♥ - 2♥ - 3♥ - 4♥)
18+6 (1♥ - 2♥ - 4♥)
19+6 (1♥ - 2♥ - 4♥)
With 25 HCPs, a game must be bid; with 23 HCPs, a game must not be bid.

Over an invitational response, go game with 14 HCPs; over a minimum response, invite with 16 HCPs and go game with 18 HCPs. Therefore, 16 is chosen as the magic number to show extras over a minimum response.