[jillybean]

I'm skilled at avoiding the 3nt trap but I am not confident of avoiding the 4nt hole.
I am getting better, I no longer use 1S:2S 4NT (this is a joke, but I often see this sequence)

As Mike has reiterated in the other thread, keycard is not a slam try, it should be used to check that we have adequate keycards and strong enough trump for a small slam or to probe for grand, checking Queen and specific Kings.

We first need to determine that we have enough, 12, tricks. I know this when we have identified a double fit or extra trump length.
Are there other ways to gauge if we have enough running tricks?

This topic keeps coming up, over and over again. Could I make a plea for a "Primer on Slam Bidding" ?

[jillybean]

If you don't have shape for 12 tricks, then I guess you need a powerhouse so you've opened strong or partner has made a 2/1

[DavidKok]

I wrote this text on the other site over a year ago, maybe that's a decent place to start.

[mikeh]

An excellent post (on the other site) by David.

As for a primer on slam bidding, presumably akin to the primer I wrote on reverses….unfortunately slam bidding is a huge topic. I think any attempt to provide detailed advice would end up, if even remotely comprehensive, as a book.

For example, slam bidding after strong notrump openings (1N, 2N, 2C the notrump) involve very different considerations than does slam bidding after 1x…..and slam bidding after 1x is different when x is a minor than when it’s a major

Plus everyone uses different methods in all of these situations. Reverses are largely universal, within fairly narrow tolerances and with some exceptions (for example, I play 1H 1N 2S as artificial, not necessarily reversing into spades).

How would one tackle, in a primer, slam bidding after 1M 2N?

Some play 2N as a limit or better raise, some play it as a gf raise, some play it as natural. Even amongst those who play it as a gf raise, there are many treatments. I suppose a primer might assume the old-fashioned approach to J2N but that’s so inferior to more modern methods that it’d feel like discussing notrump bidding on the basis that 1N showed 16-18 with no suit unstopped.

[jillybean]

Last train, non serious. I best get partner on board.

This may be the missing piece, or one of.

[DavidKok]

While new tools and gadgets can help improve a system or fix gaps, the main point is that in order to bid slams you need to accurately evaluate your combined trick-taking potential. Showing your shape and helping partner evaluate their hand in context is essential for slam bidding. This is a big part of the meaning behind the quote 'slam bidding starts at the 2-level'. In 2/1 GF in particular, giving partner room to tell whether their honours are working or not will get you much closer to being able to make the crucial decision before you are out of bidding space near 4NT.

[P_Marlowe]

Slam bidding requires, that you have a firm grip on game bidding.
You need to figure out, what strain, e.g. setting trumps or deciding to play NT below game level.

If you cant do this in a consistent matter, forget about the slam level.

[apollo1201]

You must assess
- if you have a fit in an agreed trump suit (or NT but that is usually easier with quantitative and NT ladder) robust enough
- if you have sufficient material (strength)
- if you are not off AK cashing on the opening lead
- then and only then that you are not missing 2 KC

There are recipes for each step. The last 2 are probably the most obvious, RKCB and cue bidding (although how to do it, how to extract the control that interest you, etc can be tricky).

The sufficient material can be more subtle. It also depends if you received a forcing fit (eg 1M 2m 2M 3M), or a limit fit (eg 1m 1M 3M). Some play serious or frivolous 3NT, others 3NT ok, but…

And if following cue arises, just rebidding your suit just means that you cannot commit more. Having all suits controlled does not imply slam is on.

So better chose your methods and more importantly agree them with p!

[jillybean]

From the other side:

When (not) to use Blackwood
by David Kok May 18, 2023

Most players learn some ace-asking convention, these days usually Roman Key Card Blackwood, quite early into their bridge education. Far less often this is accompanied by an explanation on when to use the convention and when to avoid it. This article contains a few observations on this point in the hopes that someone finds it useful.

Roy Hughes' "Building a Bidding System" lists four requirements for a slam:

Enough potential winners.
Solidity of trumps (or key suits, in notrump).
First-round control of at least three suits.
Control of every suit.


Of the four, the first is most important! A slam only has a good chance of making if you can reasonably expect to develop 12 tricks in addition to not losing two tricks quickly. Unfortunately it is also typically the most neglected when learning slam bidding.

Condition number two can reasonably be discovered through RKC (checking for the trump ace, king and queen). Condition number three can also be checked with RKC. Condition number four can not - and should be checked before asking for aces. Incidentally this is a part of why jumping to ask for key cards is frequently a poor idea. Use the bidding space to ask for more information and check control of the suits instead, and only then ask for aces. Keep in mind that Blackwood (or any other ace asking convention) is not a tool to get to slam, but to stay out of bad ones. The best way to think of it is as a statement "Partner, I was about to jump to 6 (or 7), but I will give us one last chance to subside at a lower level in case we are unexpectedly missing some key cards."



But what of the first requirement? There are a number of artificial treatments that can help in assessing possible combined strength for slam, including (Non)Serious 3NT, Last Train, 4♣ as a strong raise, Quantitative 4NT and control or strength asking bids. Many systems also limit the hand early in the bidding (for example, the notrump ladder, or any non-forcing or limit bid).

In addition to conventions there is also a notion of captaincy in asking for key cards. Keep in mind that bidding Blackwood is a point of no return - the bidder is stating we are (as) ready (as we'll ever be) for the slam level, excepting a last minor check. For this to be appropriate the bidder has to have a reasonable expectation that there are enough possible winners in the combined hands, and no unexpected side winners (which would make us miss a grand slam).

This usually means that the hand with an undisclosed source of tricks, i.e. a long suit that can be expected to be established, or a ruffing value, should be asking for aces. They have a better overview of the combined trick-taking potential of the hands. By contrast a hand with all aces and no filling should get out of the way and try to get partner to ask for aces, providing a much clearer picture of our combined holding. Similarly if a hand has been limited in the auction, or is much weaker than the other, partner is usually in a better position to decide whether or not we have a shot at a slam.

In general the notion of captaincy is used to describe the asymmetry of information - or, more accurately, the asymmetry in the amount of information that would be required to complete the description of the hand. When one hand has described itself very well it is almost never right for that player to then make a strong slam try. If slam was on partner was in a perfect position to investigate it.

[P_Marlowe]

An example seq., suppose you are playing 2/1 GF and the bidding starts

1H - 2D
2S (2)


(1) assume natural, but even ... whatever
(2) The question now, does openers reverse promise add. strength, or is it just shape?

You can answer this question in various ways, but if you happen to play "just shape",
to keep the bidding low, and for whatever add. reason, you need to be aware,
that you delay the limiting of openers strength to the next round.

The "just shape" approach has its merits, but it also has its cost.

Before you start discussing Serious / Last Train, ..., start with this simple auction.

And there are other similar auctions, which also raise this question: Is someone starting to
limit his hand. You may try to collect a list of those seq.

[jillybean]

1H - 2D
2S

For us, this shows a K more than minimum.
However, we may need to discuss this more as our minimums are looking sketchier and sketchier as time goes by.

[jdiana]

 jillybean, on 2024-October-02, 10:46, said:

1H - 2D
2S

For us, this shows a K more than minimum.
However, we may need to discuss this more as our minimums are looking sketchier and sketchier as time goes by.

That doesn't show extra values for us, but that's a choice. IMHO if you're opening weaker and weaker hands, then your 2/1 responses need to be really sound. I found that a lot of players (at my level anyway) seemed to put all marginal hands into their 2/1 response rather than the 1NT response, so the 1NT response gets watered down and they sometimes end up overbidding. I lean the opposite way. But there are a lot of people on here (you included ) who are much better bidders than I, so take that for what it's worth.

[P_Marlowe]

Another (basic) seq. involves FSF.
If you play 2/1 chances are, that you play FSF as GF, I dont, but it is
expert standard.
One big adv. of this style is, that opener does not need to jump to generate
a GF auction, he preserves space.
The downside is, his responses to the FSF inquiry dont limit his hand.
Add to this the fact, that playing FSF as GF requires responder regular to
stretch with inv. hand and you will a common situation, that the auction
reached the 3 level and both hands did not yet start limiting their hand,
i.e. they could still both be min, and both be max.

[DavidKok]

That's not quite an honest review. If you believe the merits of limiting the hand on a FSF sequence outweigh the space saved you can choose play the same response style over 4SGF. I'm not sure why you are stretching with an invitational hand rather than using an invitational bid.

Evaluating your hand is about much more than just limiting your hand, or limiting partner's hand. Knowing partner's shape opposite helps you tell which points are working and which are wasted. To me it is not at all clear that you do a better job assessing the combined trick-taking potential by reserving more space to show strength first, as opposited to showing more shape first. The degree of (mis)fit in the side suits is very important information.

[P_Marlowe]

 DavidKok, on 2024-October-02, 13:32, said:

That's not quite an honest review. If you believe the merits of limiting the hand on a FSF sequence outweigh the space saved you can choose play the same response style over 4SGF. I'm not sure why you are stretching with an invitational hand rather than using an invitational bid.

#1 I started with FSF as GF is expert standard.
#2 FSF was developed to ask opener, we dont have a fit, do you have a stopper in the 4th suit,
so that we can play NT. (*)
And the poster child, when to use FSF was a bal. inv. hand without a stopper in the 4th suit
You did not have a obv. bid, but playing FSF, gave you a way to handle those hands.
Playing FSF as GF means certain inv. hand dont have a great bid, that is ok, you stretch
and overbid.
This is the same, we open NT, they intervene, most of the time we throw out the inv. seq., we either
stretch or underbid.
#3 FSF as inv.+ has its own problems, you are sometimes forced to raise the 4th suit, which create murky
auctions, and you loose the ability (or at least make it harder) to find a fit in the 4th suit, if opener
is 5440.

(*) It solved add. problems.

[P_Marlowe]

 DavidKok, on 2024-October-02, 13:32, said:

<snip>
Evaluating your hand is about much more than just limiting your hand, or limiting partner's hand. Knowing partner's shape opposite helps you tell which points are working and which are wasted. To me it is not at all clear that you do a better job assessing the combined trick-taking potential by reserving more space to show strength first, as opposited to showing more shape first. The degree of (mis)fit in the side suits is very important information.

Yes it is. ... But so is the informtion about general strength.