BBO Discussion Forums: 1174 is a fun shape - BBO Discussion Forums

Jump to content

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

1174 is a fun shape

#21 User is offline   Free 

  • mmm Duvel
  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 10,728
  • Joined: 2003-July-30
  • Gender:Male
  • Location:Belgium
  • Interests:Duvel, Whisky

Posted 2007-August-25, 08:06

5♦, quick and easy
"It may be rude to leave to go to the bathroom, but it's downright stupid to sit there and piss yourself" - blackshoe
0

#22 User is offline   mikeh 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 13,999
  • Joined: 2005-June-15
  • Gender:Male
  • Location:Canada
  • Interests:Bridge, golf, wine (red), cooking, reading eclectically but insatiably, travelling, making bad posts.

Posted 2007-August-25, 13:20

I did a quick simulation, flawed because I did not have the time to do a matchpoint analysis: thus on the hands on which I 'scored' 3N and 5♦ as equivalent, some of them were no overtricks, hence a tie, and the others would have been mp wins for 3N, due to taking 10 or 11 tricks.

I did 80 deals, with partner constrained to no 6 card suit, no 5-4 shape, and 15-17 hcp and overcaller with a 6-7 card major, no side 5 card suit, and 7-16 hcp.

I also rejected 4 hands on which I felt that an overcall was inappropriate even with loose standards.

The result was:

Both 3N and 5♦ failed (3N usually did worse than 5♦ when both failed): 19

Both 3N and 5♦ worked (see above): 13

5♦ made, 3N failed: 24

3N made, 5♦ failed: 12

6♦ made: 8 times

Now, 6♦ was not clearly biddable on all 8 hands, but on 6 of them it seemed to me to be reasonable to reach the slam.

And on some of the 3N fails, but 5♦ makes or is less expensive, it would be clear not to play 3N if the 74 hand bid 3N, no stopper, but on the vast majority of those hands, opener would have had no reason to pull: usually hands with a single stopper in overcaller's suit, with the opps holding the ♦A...but one hand with opener AQx J8xx Axx AQ10..... 6♦ made and 3N failed on a low heart to Q9 tight.

On the basis of this admittedly imperfect simulation, the slow approach did better than bidding 3N, denying any major stopper for several reasons:

1. When opener passed 3N, it was often wrong. It failed 44 times out of 76 hands (one of the failures would make, and probably bid, 6♦) It was only clearly superior to 5♦ about 20 times (12 when it made and 5♦ failed, and some fraction of the time that both made, but 3N scored better).

Now this is a little unfair: on some of the 44 failures, opener wouldn't have passed 3N, and on some of them, both contracts failed.. altho 3N usually failed by at least a trick or two more.

2. Bidding 3N seems to make it very difficult to reach slam.

3. Reaching 5♦ (or 6) assured you of a good score on at least 32 of the boards. It broke even, when both made exactly, a good fraction of the time that both games made, and it gave a good edge when both games failed, which happened 19 times.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
0

#23 User is offline   whereagles 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 14,900
  • Joined: 2004-May-11
  • Gender:Male
  • Location:Portugal
  • Interests:Everything!

Posted 2007-August-25, 13:34

I'm gonna bid 3♣ and see if pard can dbl opps in 4M. If he doesn't do that, I'll bid on over 4M.
0

#24 User is offline   Foxx 

  • PipPipPipPip
  • Group: Full Members
  • Posts: 346
  • Joined: 2003-February-15
  • Gender:Male
  • Location:La Jolla, California
  • Interests:Being quick, brown, and foxy; Jumping over lazy dogs

Posted 2007-August-26, 02:46

Interesting that people have mentioned 4♣ by partner over our 3NT.

How about a direct 4♣, by us, right here? Gerber? Sweet.
0

#25 User is offline   mikegill 

  • PipPipPipPip
  • Group: Full Members
  • Posts: 296
  • Joined: 2006-May-26

Posted 2007-August-27, 09:29

Scoring: MP


I went with the blast 5♦ theory after a tank. I decided I was very unlikely to find out reliably whether 3n or 6♦ was better, and that it was very likely 5♦ was a reasonable contract. This turned out to be right here, but I thought it was an interesting problem. Also 1n (2d) 5d is a funny auction.
0

#26 User is offline   jtfanclub 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,937
  • Joined: 2004-June-05

Posted 2007-August-27, 09:57

mikeh, on Aug 25 2007, 02:20 PM, said:

I did a quick simulation, flawed because I did not have the time to do a matchpoint analysis: thus on the hands on which I 'scored' 3N and 5♦ as equivalent, some of them were no overtricks, hence a tie, and the others would have been mp wins for 3N, due to taking 10 or 11 tricks.

There will also be cases where an immediate bid (3NT or 5♦) will score more tricks than slow bidding it.

You didn't have a single case where people would bid 6♦ and go down?

How about where you bid 5 diamonds...but the opponents have a successful sacrifice of 5 of a major? Half the point of bidding 3NT directly is so that they can't find their sacrifice. 600 vs. 500 is a lot bigger deal in MPs than IMPs.
0

#27 User is offline   mikeh 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 13,999
  • Joined: 2005-June-15
  • Gender:Male
  • Location:Canada
  • Interests:Bridge, golf, wine (red), cooking, reading eclectically but insatiably, travelling, making bad posts.

Posted 2007-August-27, 10:42

jtfanclub, on Aug 27 2007, 10:57 AM, said:

mikeh, on Aug 25 2007, 02:20 PM, said:

I did a quick simulation, flawed because I did not have the time to do a matchpoint analysis: thus on the hands on which I 'scored' 3N and 5♦ as equivalent, some of them were no overtricks, hence a tie, and the others would have been mp wins for 3N, due to taking 10 or 11 tricks.

There will also be cases where an immediate bid (3NT or 5♦) will score more tricks than slow bidding it.

You didn't have a single case where people would bid 6♦ and go down?

How about where you bid 5 diamonds...but the opponents have a successful sacrifice of 5 of a major? Half the point of bidding 3NT directly is so that they can't find their sacrifice. 600 vs. 500 is a lot bigger deal in MPs than IMPs.

1. I did not try to analyze whether NS would overbid to a failing slam, but, since S will only move to slam if partner shows a good hand, and since slam will usually make opposite such a good hand (controls, diamonds.. not high card points) I would expect 5♦ making 6 will be a FAR more common outcome than 6♦ down one. My sense of the hands I looked at was that none sprang to mind on which NS would realistically overbid. Do I rule it out? No. Do I think it a significant risk? No.

2. Bidding 3N quickly or slowly was irrelevent to me. I would never aim for 3N as South. Whether N can legitimately bid 3N is not clear: the methods stipulate 3♣ as a transfer: it is far from clear that N will ever bid 3N over that... if he did, I think I would pass so long as we had an agreement that 3N showed both majors stopped and at least Axx in ♦s... Ax isn't enough... and I doubt that we have that agreement, even if we allow opener to bid 3N (ie 3♣ shows invitational + values). As for bidding 5♦ quickly, this can gain when LHO makes the wrong lead.. but much of the time, either he guesses correctly or it doesn't matter. If there were no other factor, I'd accept the argument as significant. However, 5♦ eliminates the non-trivial chance of slam, since at favourable it may well be and often would be an advance preempt.

3. As for the opps's saving: they are welcome to do so. You got the vul. wrong: we are at favourable, and if I were told that my options were to play a contract our way or defend 5major doubled, I choose door number 2, if I had no other information.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
0

#28 User is offline   jtfanclub 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,937
  • Joined: 2004-June-05

Posted 2007-August-27, 11:19

mikeh, on Aug 27 2007, 11:42 AM, said:

3. As for the opps's saving: they are welcome to do so. You got the vul. wrong: we are at favourable, and if I were told that my options were to play a contract our way or defend 5major doubled, I choose door number 2, if I had no other information.

You're right, for some reason I thought it was all red. My mistake.
0

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

1 User(s) are reading this topic
0 members, 1 guests, 0 anonymous users