BBO Discussion Forums: Round 2, Board 13 - BBO Discussion Forums

Jump to content

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

Round 2, Board 13 Another challenging part-score

#1 User is offline   inquiry 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Admin
  • Posts: 14,566
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Amelia Island, FL
  • Interests:Bridge, what else?

Posted 2010-August-23, 11:40

Scoring: IMP

Opponents do not bid.




3D=10, 4D=7, 1N=5, 3N/5D=2


3DN gnasher/catch22
3DN hrothgar/Free
3DN karlson/threenobob
2DN sallyally/joylson
1NS ant590 - crayzeejim
1NS bluecalm/redds
1NS elianna/awm
1NS jlall/hanp
1NS kristen33/jillybean
1NS peachy/lg62
1NS rogerClee/cherdano
1NS Siegmund/MSchmahl
3NTS East4Evil/sohcahtoa
3NN Flycycle/Wackojack
3NN jdonn/gib
3NS kfay/jchiu
5DN lobowolf/bkjswan
3NS mbodell - javabean
3NS olegru - driver733
3NS tlgoodwin/timg
3NS tylere / bid_em_up
--Ben--

#2 User is offline   bluecalm 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,555
  • Joined: 2007-January-22

Posted 2010-August-23, 11:44

I am not convinced at all that 3 > 1NT let alone difference that big.
I was sure we are in top spot after the bidding and seeing partner's hand.
Why exactly 3 scores so heavily here ?
0

#3 User is offline   bid_em_up 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,351
  • Joined: 2006-March-21
  • Location:North Carolina

Posted 2010-August-23, 11:46

I will object to the scoring of this board. Since double dummy defense will always find the right lead (a heart), of course, 3N will score poorly. In real life, a spade lead will give yield a 9th trick immediately, and a non-heart lead gives 3N plenty of chances, 3N will make frequently (imo). On a non-revealing auction such as, 1D-1N-3N, the chances of either major suit being led are fairly equal (again, imo).
Is the word "pass" not in your vocabulary?
So many experts, not enough X cards.
0

#4 User is offline   hrothgar 

  • PipPipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 15,724
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Natick, MA
  • Interests:Travel
    Cooking
    Brewing
    Hiking

Posted 2010-August-23, 11:49

For Free and I, this was one of the more interesting hands.

North opened 1, showing an unbalanced hand with 4+ Diamonds

South answered 3 (pass or correct)

North corrected to 3 and there we sat.

I was expecting a nice score because we were able to shut out the heart suit. I was somewhat surprised that the schizophrenic opponents were unwilling to enter into this auction, particularly given some of their other overcalls. (Like that red 2 call over a strong NT opening)

(FWIW, I think that 1NT deserves a better score)
Alderaan delenda est
0

#5 User is offline   awm 

  • PipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 8,641
  • Joined: 2005-February-09
  • Gender:Male
  • Location:Zurich, Switzerland

Posted 2010-August-23, 11:50

I agree with bluecalm here. Against 3 the opponents will often take two spades, a heart, and a club. Certainly there exist some positions where you can get ten tricks (like both spade honors onside) but I think this is against the odds. There are also positions where 3 fails (almost any time AQ are both offside).

On the other hand, 1NT has eight cold tricks on top. And there are nine tricks on a spade lead, and play for nine tricks on a club lead. There's even enough discarding pressure on the running diamonds that you could conceivably make nine tricks on a heart lead!
Adam W. Meyerson
a.k.a. Appeal Without Merit
0

#6 User is offline   JLOGIC 

  • 2011 Poster of The Year winner
  • PipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 6,002
  • Joined: 2010-July-08
  • Gender:Male

Posted 2010-August-23, 12:17

Yeah strongly disagree with the scoring here, agree with awm.
0

#7 User is offline   rogerclee 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,214
  • Joined: 2007-December-16
  • Location:Pasadena, CA

Posted 2010-August-23, 12:20

Also strongly disagree with the scoring, 3D= and 1N+1 (or more) seem extremely common.

3N and 5D don't deserve the same score, 5D is down probably 2 and 3N is down only 1 or making on a bad lead.
0

#8 User is offline   jdonn 

  • - - T98765432 AQT8
  • PipPipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 15,085
  • Joined: 2005-June-23
  • Gender:Male
  • Location:Las Vegas, NV

Posted 2010-August-23, 16:09

Save me objectors!
Please let me know about any questions or interest or bug reports about GIB.
0

#9 User is offline   cherdanno 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,640
  • Joined: 2009-February-16

Posted 2010-August-23, 20:02

Ben you really can't score this one based on double-dummy analysis. To make 10 tricks you need either both spade honors onside, or you need to
- first guess the clubs (assuming there is a way to establish a club trick), to develop a spade pitch, and then
- have one spade honor onside and guess correctly which one.

That's a lot of guessing that your double-dummy simulator did for you there.
(Btw, even double dummy my quick simulation showed 3D making 10+ tricks only 60% of the time, so I really don't know where you got the big difference between 3D and 1N from.)
"Are you saying that LTC merits a more respectful dismissal?"
0

#10 User is offline   awm 

  • PipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 8,641
  • Joined: 2005-February-09
  • Gender:Male
  • Location:Zurich, Switzerland

Posted 2010-August-23, 23:03

Agree with Cherdano.

Double dummy will always lead vs 1nt (any other lead gives good play for 150) and will always work out whether to play on clubs or spades in 3 (maximizing odds of 130). This gives a massive advantage to 3; 1nt is better single dummy.
Adam W. Meyerson
a.k.a. Appeal Without Merit
0

#11 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 2010-August-24, 01:17

hrothgar, on Aug 23 2010, 06:49 PM, said:

For Free and I, this was one of the more interesting hands.

North opened 1, showing an unbalanced hand with 4+ Diamonds

South answered 3 (pass or correct)

North corrected to 3 and there we sat.

I was expecting a nice score because we were able to shut out the heart suit. I was somewhat surprised that the schizophrenic opponents were unwilling to enter into this auction, particularly given some of their other overcalls. (Like that red 2 call over a strong NT opening)

(FWIW, I think that 1NT deserves a better score)

I wasn't happy with the auction because I had a solid suit and need only 2 tricks in your hand. But afterwards I was glad we were lucky on this one ;)
"It may be rude to leave to go to the bathroom, but it's downright stupid to sit there and piss yourself" - blackshoe
0

#12 User is offline   JLOGIC 

  • 2011 Poster of The Year winner
  • PipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 6,002
  • Joined: 2010-July-08
  • Gender:Male

Posted 2010-August-24, 01:21

Yeah the combined chances of a spade lead for 150 in 1N, and the strong chance of only getting 110 in 3D (I estimate that at much >50 % irl) make 1N better.

Also 4D is ranked way too high for the same reason.
0

#13 User is offline   jdonn 

  • - - T98765432 AQT8
  • PipPipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 15,085
  • Joined: 2005-June-23
  • Gender:Male
  • Location:Las Vegas, NV

Posted 2010-August-24, 16:59

Agree with the point that 3NT should outrank 5 since 3NT won't be down more than 1 but 5 will often be down 2.
Please let me know about any questions or interest or bug reports about GIB.
0

#14 User is offline   inquiry 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Admin
  • Posts: 14,566
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Amelia Island, FL
  • Interests:Bridge, what else?

Posted 2010-August-29, 12:41

nonsense deleted, see comments below for hint as to why
--Ben--

#15 User is offline   matmat 

  • ded
  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 3,459
  • Joined: 2005-August-11
  • Gender:Not Telling

Posted 2010-August-29, 12:45

inquiry, on Aug 29 2010, 01:41 PM, said:

As for contracts, 1NT is the limit on a heart lead, on a spade lead, you will make 2NT, not 3NT.

Hi,
am I missing something?

seems in a NT contract you're always getting six diamonds and two round aces?
0

#16 User is offline   inquiry 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Admin
  • Posts: 14,566
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Amelia Island, FL
  • Interests:Bridge, what else?

Posted 2010-August-29, 13:00

matmat, on Aug 29 2010, 01:45 PM, said:

inquiry, on Aug 29 2010, 01:41 PM, said:

As for contracts, 1NT is the limit on a heart lead, on a spade lead, you will make 2NT, not 3NT.

Hi,
am I missing something?

seems in a NT contract you're always getting six diamonds and two round aces?

Whoops.. you are right.. I will have to do some serious corrections. I only ran simulations on diamonds when i redid it.. and I miss remembered the stuff...
--Ben--

#17 User is offline   hanp 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,987
  • Joined: 2009-February-15

Posted 2010-August-29, 13:08

somehow this landed in the wrong thread.
and the result can be plotted on a graph.
0

#18 User is offline   inquiry 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Admin
  • Posts: 14,566
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Amelia Island, FL
  • Interests:Bridge, what else?

Posted 2010-August-29, 14:02

Opponents have 9 hearts and only 7 Spades, Opponents suits are:

KQJT87xxx for hearts
AQT98xx for spades

In my simple-mindedness, it seems more likely they would have longer hearts to lead and better (safer) holding to lead from (sequence) with hearts than spades.

As for contracts, 2NT is the limit on a heart lead, on a spade lead, you will make 3NT.

As for diamond contract, 3D is 100% and 4D makes in the 80% range (double dummy). So what we have is 3NT is often down one, but might make. 5D is always down one but might be down two. So 3NT has to score better than 5D.

1NT usually scores 8 tricks (120) but might score 9 (150); 3D usually scores 4 (130) but might score 9 (110).

So I see the complaints on this hand. I still think heart lead is more likely than a spade lead. I did a small group of similations where I looked at what major would be lead (major 100% of time for this). I based this on lead the longest major, or if tied, lead the major with safest sequence, or from "strongest" major card holding. In this short test, hearts was the longest half the time, and had a leadable sequence or was the strongest when tied (3-3, 4-4) the majority of the time there was a tie, the final count being heart would be lead 70% of the time (a few were subjective). So it will make 30% or so under these situations.

Clearly 3NT should score better than 5D (at worse it ties it, and it can beat it two ways.. 3NT will make on spade lead, and is never down more than one, while 5D will not make and is possibly down two). So 2MP for both is clearly wrong.

The problem is what part-score should score the best? I hate to have to admit it, but once again I reverted to matchpoint scoring this thing based upon "percentages" and what the field in the competition bid, then converted it back to a 12 point scale.

5D dropped to 0, and everyone got a point for not bidding that, then for:
3D (1/2 pts for each in diamond, plus (0.82-0.3) times the number of people in NT)
1N (1/2 pt for each in 1 Nt, plus 0.3 times number in diamonds)
3N (1/2 pt for each in 3NT, plus 0.3 times those in both 1NT and diamonds)

If I did this right, the anticipate mp were:
5D 0 ----------> round up on a 12 point scale to 0
3D 10.82------> round up on a 12 point scale to 7
3N 8.1 --------> round up on a 12 point scale to 5
1N 3.6 --------> round up on a 12 point scale to 4

For the "round up" I convert the Mp calculated on a 20 top score to a 12 top score and then increase to the nearest whole number.
--Ben--

#19 User is offline   JLOGIC 

  • 2011 Poster of The Year winner
  • PipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 6,002
  • Joined: 2010-July-08
  • Gender:Male

Posted 2010-August-29, 14:19

3N now scores higher than 1N?

It seems like your formula is off. You make 1N>3D only 30 % of the time. However, as far as I can tell, 1N is better than 3D the 30 % of the time it gets a spade lead, plus the 20 % of the time that 3D only makes 3.

So if my math is right, 1N>3D 44 % of the time.

Also, 1N should get a point 70 % of the time vs 3N, and 100 % of the time against 5D.
0

#20 User is offline   hanp 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,987
  • Joined: 2009-February-15

Posted 2010-August-29, 14:31

I think the method is good Ben, but you forgot to give those in 1NT points for those in 3NT going down.
and the result can be plotted on a graph.
0

  • 2 Pages +
  • 1
  • 2
  • 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