Bidding quiz (hand)

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Kenny McCormack

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Jul 5, 2022, 2:47:23 PM7/5/22
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This time, you get to see two hands:

North has: AKxxx,QJx,x,Qxxx
South has: xx,Kxxx,Axx,AKJx

South dealer, vul and/or form of scoring unknown.

System: Assume SAYC, no other agreements.

What contract do you want to be in? How do you get there?
Note: Opps will bid (overcall) and raise diamonds if possible.

In particular, assume S will open a 15-17 1NT, and take it from there.

--
"There's no chance that the iPhone is going to get any significant market share. No chance." - Steve Ballmer

John Hall

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Jul 5, 2022, 3:53:45 PM7/5/22
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In message <ta20vp$2fa4p$1...@news.xmission.com>, Kenny McCormack
<gaz...@shell.xmission.com> writes
>This time, you get to see two hands:
>
>North has: AKxxx,QJx,x,Qxxx
>South has: xx,Kxxx,Axx,AKJx
>
>South dealer, vul and/or form of scoring unknown.
>
>System: Assume SAYC, no other agreements.
>
>What contract do you want to be in? How do you get there?
>Note: Opps will bid (overcall) and raise diamonds if possible.


Whilst 6C will make on a good day, as a lot of pairs are likely to be in
3NT going down I think I'll be conservative and settle for game. 4S
making will beat 5C and tie with 5C+1, but spades 4-2 could make 4S
tricky. I find it hard to decide between 4S and 5C.

>
>In particular, assume S will open a 15-17 1NT, and take it from there.
>

I came up with a plausible sequence, but then realised that I'd
forgotten about the EW diamond intervention that you mentioned. And now
I need to go and do something else.
--
John Hall
"Home is heaven and orgies are vile,
But you *need* an orgy, once in a while."
Ogden Nash (1902-1971)

Fred.

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Oct 23, 2022, 2:04:57 PM10/23/22
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Since 3NT makes only if the diamonds are 6-3 or more skewed and the
heart ace is in the short diamond hand, and 4S is dicey, I want to be in a
club part score at match points, 5C at IMP scoring. But, I have no clue how
to get to the club part score, as the hands seem to add up to at least 5C,
with 6C possible from responder's point of view.

If the auction starts out 1NT-(2D)-3S we will end in 3NT. Since responder
has a good hand for suit play, I think the auction might go

1NT (2D) 3D (pass)
3H (pass) 3S (pass)
4C (pass) 5C (all pass)

5C is a reasonable call since with a max spade fit opener will
correct to spades.

However, I don't really like 5C since I don't have the entries to
ruff 2 diamonds and draw 4 rounds of trump.

Fred.

cshe...@gmail.com

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Oct 23, 2022, 9:28:36 PM10/23/22
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On Sunday, October 23, 2022 at 1:04:57 PM UTC-5, Fred. wrote:

> Since 3NT makes only if the diamonds are 6-3 or more skewed and the
> heart ace is in the short diamond hand, and 4S is dicey, I want to be in a
> club part score at match points, 5C at IMP scoring. But, I have no clue how
> to get to the club part score, as the hands seem to add up to at least 5C,
> with 6C possible from responder's point of view.
>
> If the auction starts out 1NT-(2D)-3S we will end in 3NT. Since responder
> has a good hand for suit play, I think the auction might go
>
> 1NT (2D) 3D (pass)
> 3H (pass) 3S (pass)
> 4C (pass) 5C (all pass)
>
> 5C is a reasonable call since with a max spade fit opener will
> correct to spades.
>
> However, I don't really like 5C since I don't have the entries to
> ruff 2 diamonds and draw 4 rounds of trump.
>
> Fred.

www.aeyec.com/bidbase/bid quiz in groups.jpg

FWIW, my BidBase program shows in the screen shot above that mixing the E-W cards 100 times and doing DDA analysis on each, the optimum contracts from N or S are 6C, 5H, and 4S.

Nelson

Peter Smulders

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Oct 24, 2022, 6:42:53 AM10/24/22
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That link does not work.
From your analysis, how often 6C will fail?

cshe...@gmail.com

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Oct 24, 2022, 9:47:27 AM10/24/22
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> > www.aeyec.com/bidbase/bid quiz in groups.jpg
> >
> > FWIW, my BidBase program shows in the screen shot above that mixing the E-W cards 100 times and doing DDA analysis on each, the optimum contracts from N or S are 6C, 5H, and 4S.
> >
> That link does not work.
> From your analysis, how often 6C will fail?

I tested the URL after putting in the post and it worked. I tested it
again just now and it works fine. You can't just click on it.
You have to copy-and-paste it into your browser.

As to how often 6C will fail... The question of what percentage
for the program to use as a basis for making a bid is one that I
have searched for and asked experts about and never gotten a
good answer.

In fact, here is something from one of my documentation files:

This brings up the question of how high the percentage of
making at least a certain number of tricks should be for BB
to bid that number of tricks. In matchpoints, where it is
more important to get a positive score even if it isn't an
absolute top, choosing a contract which makes at least 55%
of the time may be better than in team play where bidding a
50% game is better.

In Bobby Wolff's July 5, 2022, Aces newspaper column, he
says about bidding a close game: "Bid one more [after 1S-3S]
and be prepared to find yourself in a no-play contract from
time to time." "From time to time" is generally understood
to mean "infrequently" which in turn is defined as "rarely".

Even if 4S makes 60% of the time, the 40% it doesn't make is
hardly "rarely" which would be more like less than 5% that
it doesn't make, yet it surely can't be right to bid only contracts
which make 95+% of the time.

In the August 2022 ACBL Bridge Bulletin's Bidding Box, page 39,
is the comment: Responder's two nice cards can be barely enough
to scrounge up a raise to game. Although game is not at all cold,
it is probably worth being in.

A game is considered "cold" if it can't be defeated double dummy.
A game might not be cold, but it may have enough play to make
game anyway, which is where the "probably worth being in" comment
comes into play.

The most recent info I've seen about what % to shoot for
when bidding game was in the Sept. 2022, Bridge Bulletin.
The article is on page 67 and was written by Dr. James Marsh
Sternberg.

He says that a 26-HCP 3NT contract will make 80% of the time,
but doesn't say how often 3NT would make with 25 HCP or 24 HCP.
He does talk about how inviting with 8 HCP and ending in a 24-HCP
game is a bad thing, but he doesn't give any actual numbers for
what percentage of the time 3N will make with 24 HCP, nor, if
it's (say) 51% of the time, is that still a bad thing, because
at this time, when the BidBase Practice program's Double Dummy
Analysis shows a contract making 51% of the time, it will bid it.
(The 51% can easily be changed to anything else in the code.)
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