[ruleof15]

Bidding 2NT in response to a major suit opening should show 12+ points and 4+card support if you only open 13+HCP hands or 13+ if you open 12 point hands. It also denies holding a singleton or void. This is how the convention is described by ACBL. Should you have a singleton or void, a splinter bid is used. Responder's points are figured with allowance for shortage and length. Playing differently requires an alert. A splinter bid shows about 12 points.

[TylerE]

I have literally never heard this description ever. Not sure where you dredged it up.

PS: Any variant of J2NT requires an alert.

[Vampyr]

A splinter is made on the hand not good enough to bid Jacoby. You are hoping to get to a skinny slam based on shape, not power. Your hand should also be very specific, since you are using up so much room. I prefer to make them with three or four controls, and without stray Queens or Jacks, because you’re not make the thin slams with these, And anyway these might push your point count enough to bid a GF raise.

You can also sprinter with a monster, and bid on over your partners signoff. But this is rare.

[mycroft]

The thing I was always told was that you splintered to make partner captain, and bid 2NT when you needed to be captain (or when you were balanced, of course).

That basically boils down to "splinter on a narrow range of hands around GF strength, where partner can work out if their opener is an effective 11 count or an effective 18." Which is what people are saying; it's just a "understand the game" way of thinking about it rather than a "follow the rules" way.
as Vampyr says, you can have the hand where "I know you have an effective 11, I just want to know if it's the *right* effective 11" and you splinter and ignore partner's signoff. But again, your "ignore" is not going to be "ole Black", it's going to finish describing your hand so that partner still is captain.

[ruleof15]

TylerE, on 2020-May-04, 19:59, said:

I have literally never heard this description ever. Not sure where you dredged it up.

PS: Any variant of J2NT requires an alert.

[Bad_Wolf]

You can always play split ranges, eg. 1h-2s/1s-2n as any SPL say 7-9/14+ and direct is 10-13 or whatever.

[johnu]

Vampyr, on 2020-May-04, 20:44, said:

A splinter is made on the hand not good enough to bid Jacoby.

A lot of people in the US are using Jacoby as a 2 way bid. Either game forcing or up to a limit raise. 1M - 3M is preemptive.

[Vampyr]

johnu, on 2020-May-06, 20:40, said:

A lot of people in the US are using Jacoby as a 2 way bid. Either game forcing or up to a limit raise. 1M - 3M is preemptive.

Yes, I have heard of this and even played it. It is not called Jacoby by the way. Anyway, the responses are not as effective as in Jacoby or a modified version. It is much harder to get to slams (the principal purpose of Jacoby 2NT) when you have to also decide whether to be in game or a partscore. Better to use Bergen raises, or something else, like using 2♣ as natural or an invitational raise, or some other scheme.

The other problem is that you say 2-way, but that does not seem to be the case. It is continuous from invitational to GF and slam-going. Continuous ranges are never best.

[blackshoe]

It shouldn't be called Jacoby, because it's not Jacoby. But people are so used to "a 2NT response to 1M is Jacoby" that they call it that even when that's wrong. Which is why explaining a bid with the name of a convention is wrong.

[John_H]

ruleof15, on 2020-May-04, 16:58, said:

Bidding 2NT in response to a major suit opening should show 12+ points and 4+card support if you only open 13+HCP hands or 13+ if you open 12 point hands. It also denies holding a singleton or void. This is how the convention is described by ACBL. Should you have a singleton or void, a splinter bid is used. Responder's points are figured with allowance for shortage and length. Playing differently requires an alert. A splinter bid shows about 12 points.

The 2NT bid agrees the trump suit, and indicates you have a minimum expectation of playing in game, and is not 'strict' in terms of shape or count. The bids after 2NT are a matter of partnership style - personally I like ascending cue bids for any slam interest, 3 of the opening suit for sub-par openings, 3NT for 4 card suit openings (won't apply if you play SAYC or other 5 card major systems) and 4 of the opening suit as fairly minimum (<15), shapeless hands.
For me, splinter bids suggest a more shapely hand with game possible because of distribution rather than HCP strength, and with the specified shortage as the main feature of interest (less likely to hold AK in a side suit for example).

[BillHiggin]

Vampyr, on 2020-May-04, 20:44, said:

A splinter is made on the hand not good enough to bid Jacoby. You are hoping to get to a skinny slam based on shape, not power. Your hand should also be very specific, since you are using up so much room. I prefer to make them with three or four controls, and without stray Queens or Jacks, because you’re not make the thin slams with these, And anyway these might push your point count enough to bid a GF raise.

You can also sprinter with a monster, and bid on over your partners signoff. But this is rare.

I think there are possible agreements (which are likely to be overly complicated) that may allow you to sensibly splinter and then bid on. However, if one just tries this without those additional agreements, you can end up with a horrible mess. Take the not uncommon auction where one partner splinters and then invokes blackwood over openers attempt to sign off. Now, one player will know how many aces are held while the other will know how much duplication of values exists in responders short suit -- good luck with that!

[FelicityR]

blackshoe, on 2020-May-08, 12:42, said:

It shouldn't be called Jacoby, because it's not Jacoby. But people are so used to "a 2NT response to 1M is Jacoby" that they call it that even when that's wrong. Which is why explaining a bid with the name of a convention is wrong.

I'm not disagreeing with you as I know you are an experienced director, blackshoe, but can you clarify this further. I thought that most players using a 5M system would understand if you described a bid as a "Jacoby 2NT" in response to opening one of a major.

Calling it just "Jacoby" would perhaps be wrong, but "Jacoby 2NT" is universal, or is it? Now that there are now variations where it is not universally forcing to game (as detailed above) change its meaning, and the way its alerted, in some way?

[Vampyr]

FelicityR, on 2020-June-03, 03:36, said:

I'm not disagreeing with you as I know you are an experienced director, blackshoe, but can you clarify this further. I thought that most players using a 5M system would understand if you described a bid as a "Jacoby 2NT" in response to opening one of a major.

Maybe. But why do you want to use a convention name instead of explaining what the bid means?

Quote

Calling it just "Jacoby" would perhaps be wrong, but "Jacoby 2NT" is universal, or is it? Now that there are now variations where it is not universally forcing to game (as detailed above) change its meaning, and the way its alerted, in some way?

Well, when the bid is 2NT there is no difference between the explanations “Jacoby” and “Jacoby 2NT”.

Also there are many variations— different response schemes, using 1♥-2♠ for the game force, even the inv+ 2NT bid which is too far away to be called a variation.

But why do you want to use a convention name instead of explaining what the bid means?

[Zelandakh]

Bad_Wolf, on 2020-May-06, 17:02, said:

You can always play split ranges, eg. 1h-2s/1s-2n as any SPL say 7-9/14+ and direct is 10-13 or whatever.

1♥
==
2♥ = weak raise
2♠ = mini-splinter or maxi-splinter
... - 2N = relay
... - ... - 3m = INV with 0-1 in m
... - ... - 3♥ = INV with 0-1 ♠
... - ... - 3♠ = void maxi-splinter
... - ... - ... - 3N = relay
... - ... - ... - ... - 4m = void in m
... - ... - ... - ... - 4♥ = ♥ void
... - ... - 3N = maxi-splinter with singleton ♠
... - ... - 4m = maxi-splinter with singleton in m
2N = GF raise
... - 3♣ = min with shortage
... - 3♦ = extras with shortage
... - 3♥ = min without shortage
... - 3♠ = extras without shortage
... - others = max
3♣ = INV raise
3♦ = mixed raise
3♥ = PRE raise
3♠ = void splinter
... - 3N = relay
... - ... - 4m = void in m
... - ... - 4♥ = ♥ void
3N = raise with singleton ♠
4m = raise with singleton in m
4♥ = PRE raise
--

1♠
==
2♠ = weak raise
2N = mini-splinter or maxi-splinter
... - 3♣ = relay
... - ... - 3♦ = INV with 0-1 ♦
... - ... - 3♥ = INV with 0-1 ♥
... - ... - 3♠ = INV with 0-1 ♣
... - ... - 3N = void maxi-splinter
... - ... - ... - 4♣ = relay
... - ... - ... - ... - 4♦ = ♦ void
... - ... - ... - ... - 4♥ = ♥ void
... - ... - ... - ... - 4♠ = ♣ void
... - ... - 4m = maxi-splinter with singleton in m
... - ... - 4♥ = maxi-splinter with singleton ♥
3♣ = GF raise
... - 3♦ = min with shortage
... - 3♥ = extras with shortage
... - 3♠ = min without shortage
... - 3N = extras without shortage
... - others = max
3♦ = INV raise
3♥ = mixed raise
3♠ = PRE raise
3N = void splinter
... - 4♣ = relay
... - ... - 4♦ = ♦ void
... - ... - 4♥ = ♥ void
... - ... - 4♠ = ♣ void
4m = raise with singleton in m
4♥ = raise with singleton ♥
4♠ = PRE raise
--

[P_Marlowe]

Vampyr, on 2020-June-03, 14:59, said:

<snip>
But why do you want to use a convention name instead of explaining what the bid means?

A name is a short cut.
Lots of peoble associate a Jacoby 2NT GF raise with a 4+ raise, i.e. you would have to say / write
"GF raise with 4+" (*), instead of just "J2NT".
An alternative example, maybe Precision 2C ( may mean 5+C, when 5C than a additional 4 card major suit).

But obviously I agree, it is usually better (even faster) to give a short explanation of the meaning,
instead of the name.


(*) This assumes, that the person I am talking to, knowes, what GF stands for, maybe GF fit raise would
be better ( and longer ).

[pescetom]

P_Marlowe, on 2020-June-04, 05:58, said:

A name is a short cut.
Lots of peoble associate a Jacoby 2NT GF raise with a 4+ raise, i.e. you would have to say / write
"GF raise with 4+" (*), instead of just "J2NT".
An alternative example, maybe Precision 2C ( may mean 5+C, when 5C than a additional 4 card major suit).

But obviously I agree, it is usually better (even faster) to give a short explanation of the meaning,
instead of the name.


(*) This assumes, that the person I am talking to, knowes, what GF stands for, maybe GF fit raise would
be better ( and longer ).

"GF raise 4+" seems sufficient to me.
They can always ask what GF means if really in doubt.

Nobody in my club has even heard of Jacoby 2NT, another problem of using convention names.

[mycroft]

There's a reason the ACBL (and other Bridge organizations) says "The name of the convention is not sufficient":

• you might not actually be playing it
  
• They might know that the convention is, but they have it wrong
  
• You may not be playing *all* of it
  
• you play a variant that is non-standard
  
• they may not know what it is (and get the no-win option of "look like an idiot and ask" or "be an idiot and play without understanding")
  
• They may know it as something else: cue the "No, but I play Hamilton" story, but without the ego or the knowledge

The WBF allows convention names, but only when you play them *exactly* the way they're described in their big book (and even then, that's for marking the convention card, not for explanations). Any difference, and you have to spell it all out.

It's a nice shortcut, when discussing things with friends or partners. It's not a *legal* shortcut when it comes to explaining for the opponents. F ur xtra 6 🔑s r wrth ↑ than the opponents understanding, please don't play in my game. After all, if shortcuts are so important for you, you'll be fine with "4415-1, <1C" for my 2D opening, right?

[Tramticket]

A convention name is never an adequate explanation to opponents.


The reason it is inadequate can be seen from:

blackshoe, on 2020-May-08, 12:42, said:

It shouldn't be called Jacoby, because it's not Jacoby.

I have a book in front of me by Brian Senior where he is describing Jacoby 2NT:

Quote

As with most popular conventions which have been around for a while, there are now several modifications to the basic idea in use. The one I will describe come from Chip Martel, a multiple world champion from USA.

This book is over 25 years old - not some recent trend. If experts on both sides of the Atlantic think that this non-game forcing version is Jacoby, I will continue calling it Jacoby in general conversation and continue to describe the bid to opponents as "four-card support, invitational or stronger".

[blackshoe]

Tramticket, on 2020-June-04, 09:47, said:

This book is over 25 years old - not some recent trend. If experts on both sides of the Atlantic think that this non-game forcing version is Jacoby, I will continue calling it Jacoby in general conversation and continue to describe the bid to opponents as "four-card support, invitational or stronger".

In general conversation, you can call it whatever you want. You should be willing to accept that you might not be understood. In explaining your bid (or your partner's, f2f) the name alone, as you know, is not legal, and I would say it is not acceptable to be willing to accept that you might not be understood.

[blackshoe]

FelicityR, on 2020-June-03, 03:36, said:

I'm not disagreeing with you as I know you are an experienced director, blackshoe, but can you clarify this further. I thought that most players using a 5M system would understand if you described a bid as a "Jacoby 2NT" in response to opening one of a major.

Calling it just "Jacoby" would perhaps be wrong, but "Jacoby 2NT" is universal, or is it? Now that there are now variations where it is not universally forcing to game (as detailed above) change its meaning, and the way its alerted, in some way?

If it's a 2NT bid, as someone else pointed out, there's no difference between "Jacoby" and "Jacoby 2NT" except that some of our more... confused... players might think you mean "Jacoby transfer" in the former case. Or even, I suppose, in the latter.

The convention known as "Jacoby 2NT", showing a four card raise of partner's major suit opening bid, with game forcing values, balanced unless 16+ HCP when responder might have a singleton, is very common in the United States and, I think, in Canada. Don't know about Mexico. It is not universal even in those places, and I doubt it ever has been. It is certainly not universal, and probably not even common, in the rest of the world.

The ACBL's regulations (and those of at least some other authorities) specify that naming a convention is not adequate explanation of the meaning of that convention. So it is illegal to "explain" by naming the convention. That alone should lead people to refrain from doing so. It doesn't matter whether you think your opponent would understand exactly what you meant. It doesn't even matter if they do understand what you meant. It's kind of like saying to the cop who stops you for speeding at 3 AM "gee, officer, nobody else is on the road, what's the problem?"