BBO Discussion Forums: What does this bidding sequence tell you about N/S hands - BBO Discussion Forums

Jump to content

  • 3 Pages +
  • 1
  • 2
  • 3
  • You cannot start a new topic
  • You cannot reply to this topic

What does this bidding sequence tell you about N/S hands

#21 User is offline   pescetom 

  • PipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 7,481
  • Joined: 2014-February-18
  • Gender:Male
  • Location:Italy

Posted 2020-May-01, 15:43

View Postbluenikki, on 2020-May-01, 13:26, said:

It *should* be that asking without the queen is very rare. Because your chances of going down in 5 are then very real.


It is quite frequent to ask for the Queen with the intention of discovering this and if positive then side King information also (however you show it). That's why it is part of the convention in the first place. Obviously it is one kettle of fish to do so knowing you can stop in 5 if the answer is no and another to force to 6 whatever the answer.
0

#22 User is offline   bluenikki 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 575
  • Joined: 2019-October-14

Posted 2020-May-01, 17:55

View Postpescetom, on 2020-May-01, 15:43, said:

It is quite frequent to ask for the Queen with the intention of discovering this and if positive then side King information also (however you show it). That's why it is part of the convention in the first place. Obviously it is one kettle of fish to do so knowing you can stop in 5 if the answer is no and another to force to 6 whatever the answer.


If the partnership is missing the trump queen, the chance of 2 trump losers is significant. And it is very rare for the rest of the hand to be so solid that the chance of a 3rd loser can be discounted. And if it is that solid, then what are you doing playing in a suit?
0

#23 User is offline   miamijd 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 737
  • Joined: 2015-November-14

Posted 2020-May-01, 17:59

View Postpescetom, on 2020-May-01, 11:58, said:

Because with 0341 a 4NT RKCB of hearts becomes a real SNAFU.

With 4NT as the ask in hearts you already have the problem that a reply 2 keycards + Queen would take you above 5.
Now you are adding the problem that with 1 keycard (more likely than 0 or 3) you cannot ask for the Queen without forcing to slam.


That's why 4S, not 4NT, is the key card bid for H.
0

#24 User is online   smerriman 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,899
  • Joined: 2014-March-15
  • Gender:Male

Posted 2020-May-01, 19:28

View Postbluenikki, on 2020-May-01, 17:55, said:

If the partnership is missing the trump queen, the chance of 2 trump losers is significant. And it is very rare for the rest of the hand to be so solid that the chance of a 3rd loser can be discounted. And if it is that solid, then what are you doing playing in a suit?

That's the purpose of asking for the queen when missing one keycard; if you're also missing the queen, you stop short of slam. And why all of the comments above are about making sure the asking bid has enough room to stop at the 5 level in that situation.

If you're likely to go down at the 5 level when missing 1 keycard and the queen, you shouldn't be asking for aces in the first place.
0

#25 User is offline   AL78 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,996
  • Joined: 2019-October-13
  • Gender:Male
  • Location:SE England
  • Interests:Bridge, hiking, cycling, gardening, weight training

Posted 2020-May-02, 06:39

View Postpescetom, on 2020-May-01, 11:58, said:

Because with 0341 a 4NT RKCB of hearts becomes a real SNAFU.

With 4NT as the ask in hearts you already have the problem that a reply 2 keycards + Queen would take you above 5.
Now you are adding the problem that with 1 keycard (more likely than 0 or 3) you cannot ask for the Queen without forcing to slam.


I'm not going to lose sleep over a niggle with an extremely unlikely chance of showing up. Such a situation has never happened in the 22 years I have been playing bridge.
0

#26 User is offline   AL78 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,996
  • Joined: 2019-October-13
  • Gender:Male
  • Location:SE England
  • Interests:Bridge, hiking, cycling, gardening, weight training

Posted 2020-May-02, 06:43

View Postmiamijd, on 2020-May-01, 17:59, said:

That's why 4S, not 4NT, is the key card bid for H.


1 - 4
4 - 4

Is 4 key card for hearts or is it a cue bid?
0

#27 User is offline   Gerardo 

  • PipPipPipPipPipPip
  • Group: Admin
  • Posts: 2,482
  • Joined: 2003-February-12
  • Gender:Male
  • Location:Dartmouth, NS, Canada

Posted 2020-May-02, 08:35

Cue bid unless you're playing it as RKCB (either way).
If you do play 4 as RKCB, then 4NT becomes the cuebid, most probably showing a void in this sequence (or 2 fast losers somewhere; a reason not to ask).


#28 User is offline   Cyberyeti 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 13,991
  • Joined: 2009-July-13
  • Location:England

Posted 2020-May-02, 10:04

View PostAL78, on 2020-May-02, 06:43, said:

1 - 4
4 - 4

Is 4 key card for hearts or is it a cue bid?


For us keycard with 4N as the spade cue but that depends on agreements. (this auction is different for us as 4 is a void splinter, but the reply covers analogous situations)
0

#29 User is offline   bluenikki 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 575
  • Joined: 2019-October-14

Posted 2020-May-02, 12:02

View Postsmerriman, on 2020-May-01, 19:28, said:

That's the purpose of asking for the queen when missing one keycard; if you're also missing the queen, you stop short of slam. And why all of the comments above are about making sure the asking bid has enough room to stop at the 5 level in that situation.

If you're likely to go down at the 5 level when missing 1 keycard and the queen, you shouldn't be asking for aces in the first place.


You may not be *likely* to be set at 5. But that's not the issue. Going down 40% of the time is unacceptable. If you're missing QJxxx in trump and an ace ....
0

#30 User is online   smerriman 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,899
  • Joined: 2014-March-15
  • Gender:Male

Posted 2020-May-02, 14:28

View Postbluenikki, on 2020-May-02, 12:02, said:

You may not be *likely* to be set at 5. But that's not the issue. Going down 40% of the time is unacceptable. If you're missing QJxxx in trump and an ace ....

Then it was probably wrong to use Blackwood in the first place. Or if it weren't, the probability of missing QJxxx and an ace was low enough when using it that the chance of making slam outweighs that cost.

I'm still not quite of the point you're trying to make - if Blackwood is right in a given auction, I'd still say it's a pretty even split as to whether it's the person with or without the queen who is using it. Definitely not the case that most of the time you shouldn't ask without the queen.

Simple example matching your criteria..



Are you saying neither player should go past the 4 level because if you're missing QJxxx and an A you might be going down in 5 33% of the time?
0

#31 User is offline   bluenikki 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 575
  • Joined: 2019-October-14

Posted 2020-May-02, 14:57

View Postsmerriman, on 2020-May-02, 14:28, said:

Then it was probably wrong to use Blackwood in the first place. Or if it weren't, the probability of missing QJxxx and an ace was low enough when using it that the chance of making slam outweighs that cost.

I'm still not quite of the point you're trying to make - if Blackwood is right in a given auction, I'd still say it's a pretty even split as to whether it's the person with or without the queen who is using it. Definitely not the case that most of the time you shouldn't ask without the queen.

Simple example matching your criteria..



Are you saying neither player should go past the 4 level because if you're missing Q and J and an A you might be going down in 5 33% of the time?


Absolutely!!!!!

Down in 5 of a major 33% of the time is a catastrophe.
0

#32 User is online   smerriman 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,899
  • Joined: 2014-March-15
  • Gender:Male

Posted 2020-May-02, 15:01

But it's not 33% of the time. It's 33% multiplied by the chance that partner doesn't have an extra trump AND doesn't have the jack or queen of trumps AND doesn't have the missing ace.. which is very small. Whereas if he has some of those, you'll be missing out on a decent chance of slam.

Next time you aren't missing the ace, and you've missed a 67% slam - you don't consider that a catastrophe?

[edit]In fact given those spot cards I randomly added, there's only a 15% chance of two trump losers.
0

#33 User is offline   bluenikki 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 575
  • Joined: 2019-October-14

Posted 2020-May-02, 15:44

View Postbluenikki, on 2020-May-02, 14:57, said:

Absolutely!!!!!

Down in 5 of a major 33% of the time is a catastrophe.


OK there is 6NT even with 2 losers.

Do *you* have a method of reaching 5NT in the event the king is missing?
0

#34 User is offline   bluenikki 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 575
  • Joined: 2019-October-14

Posted 2020-May-02, 15:46

View Postsmerriman, on 2020-May-02, 15:01, said:

But it's not 33% of the time. It's 33% multiplied by the chance that partner doesn't have an extra trump AND doesn't have the jack or queen of trumps AND doesn't have the missing ace.. which is very small. Whereas if he has some of those, you'll be missing out on a decent chance of slam.

Next time you aren't missing the ace, and you've missed a 67% slam - you don't consider that a catastrophe?

[edit]In fact given those spot cards I randomly added, there's only a 15% chance of two trump losers.


gloing down in 5 major 15% of the time is a catastrophe.
0

#35 User is online   smerriman 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,899
  • Joined: 2014-March-15
  • Gender:Male

Posted 2020-May-02, 16:19

You're not reading what I wrote or not understanding probability. It's not 15% of the time you investigate slam, it's 15% of the worst case.

A quick sim - suppose South just blasts Blackwood over 4D (not necessarily best, but comparing to stopping in 4S) and goes to slam unless missing two keys or one and the queen.

41% of the time you stop in 5. 14% of these you go down, 86% you make.
59% of the time you bid slam. 80% of these you make slam, 20% you don't.

Despite the fact that 14% of time you're going down when in 5M, in MPs you're scoring 60% by bidding on, so stopping in 4 is clearly wrong. And at IMPs the amount you gain from the making slams far outweigh any losses.
0

#36 User is offline   bluenikki 

  • PipPipPipPipPip
  • Group: Full Members
  • Posts: 575
  • Joined: 2019-October-14

Posted 2020-May-02, 16:28

View Postsmerriman, on 2020-May-02, 16:19, said:

You're not reading what I wrote or not understanding probability. It's not 15% of the time you investigate slam, it's 15% of the worst case.

A quick sim - suppose South just blasts Blackwood over 4D (not necessarily best, but comparing to stopping in 4S) and goes to slam unless missing two keys or one and the queen.

41% of the time you stop in 5. 14% of these you go down, 86% you make.
59% of the time you bid slam. 80% of these you make slam, 20% you don't.

Despite the fact that 14% of time you're going down when in 5M, in MPs you're scoring 60% by bidding on, so stopping in 4 is clearly wrong. And at IMPs the amount you gain from the making slams far outweigh any losses.


In the example, the right way is to investigate slam and if it looks poor STOP IN 5N, making 100% of the time. Can you do that?
0

#37 User is online   smerriman 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,899
  • Joined: 2014-March-15
  • Gender:Male

Posted 2020-May-02, 16:34

Nope. But investigating slam still comfortably beats your strategy of never asking without the queen.
0

#38 User is offline   DavidKok 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,349
  • Joined: 2020-March-30
  • Gender:Male
  • Location:Netherlands

Posted 2020-May-02, 16:36

View Postsmerriman, on 2020-May-02, 14:28, said:

Then it was probably wrong to use Blackwood in the first place. Or if it weren't, the probability of missing QJxxx and an ace was low enough when using it that the chance of making slam outweighs that cost.

I'm still not quite of the point you're trying to make - if Blackwood is right in a given auction, I'd still say it's a pretty even split as to whether it's the person with or without the queen who is using it. Definitely not the case that most of the time you shouldn't ask without the queen.

Simple example matching your criteria..



Are you saying neither player should go past the 4 level because if you're missing QJxxx and an A you might be going down in 5 33% of the time?


You are cold for 6NT (2 spades, 3 hearts, 4 diamonds, 3 clubs) and want to stop in 5S, often going -1? Why?

Slightly less tongue-in-cheek, the problem here is that these hands were artificially constructed to have lots of points and a fit in spades but an obvious flaw - both hands are of notrump shape, and some of the values are slow. Both north and south should think twice before steering to a trump contract - why bid 4 over 3NT, or head for a trump contract as north with known balanced partner and no ruffing value?
0

#39 User is online   smerriman 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,899
  • Joined: 2014-March-15
  • Gender:Male

Posted 2020-May-02, 16:39

View PostDavidKok, on 2020-May-02, 16:36, said:

You are cold for 6NT (2 spades, 3 hearts, 4 diamonds, 3 clubs) and want to stop in 5S, often going -1? Why?

Not sure what you're saying - bluenikki is stating that neither player should bid past 4. I'm saying this is clearly wrong (whatever the right approach is).

But yes, I shouldn't have made the example so balanced.
0

#40 User is offline   blackshoe 

  • PipPipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 17,619
  • Joined: 2006-April-17
  • Gender:Male
  • Location:Rochester, NY

Posted 2020-May-08, 13:13

View Postpescetom, on 2020-May-01, 11:58, said:

Because with 0341 a 4NT RKCB of hearts becomes a real SNAFU.

With 4NT as the ask in hearts you already have the problem that a reply 2 keycards + Queen would take you above 5.
Now you are adding the problem that with 1 keycard (more likely than 0 or 3) you cannot ask for the Queen without forcing to slam.

If you want to keep 0341 responses, or really even if you don't, you should play Kickback. Jeff Rubens explained why in his very good series of articles in The Bridge World on "The Useful Space Principle".
--------------------
As for tv, screw it. You aren't missing anything. -- Ken Berg
I have come to realise it is futile to expect or hope a regular club game will be run in accordance with the laws. -- Jillybean
0

  • 3 Pages +
  • 1
  • 2
  • 3
  • You cannot start a new topic
  • You cannot reply to this topic

2 User(s) are reading this topic
0 members, 2 guests, 0 anonymous users