Balancing over preempt, simulations
#1
Posted 2004-July-18, 15:08
South's hand:
♠ Jxx
♥ JT8xxx
♦ ATx
♣ x
MP, None vuln
pass (3♣) pass (pass)
?
Most people agred that balancing at IMPS would be crazy, but quite a few posters argued that 3♥could be a good gamble at MP.
This position is quite different from the accepted standards of balancing, and the discussion was quite "hot"
As I like to verify things objectively, I decided toi run a simulation, keeping Souith's hand and using the following constraints:
1- west (the preemptor) has <10 hcp and at most 2 losers in clubs, no side 4 card suit
2- north (balancer's pard) has either 7+ losers or a good balanced hand unsuitable for t/o double (with 4+ clubs and wasted values in clubs), but not strong enough to bid 3NT (e.g. a 18 balanced hand)
3- east (preemptor pard) has <16 hcp and has no 3 card support in clubs nor Hx in clubs: with such holdings, it is usual either to raise preemptively if weak, OR to bid 3NT if good hand.
The simulations assume that balancer's pard raises 3H to 4H if he has at least an opening hand playing strength with 3 card support in hearts.
I expected that the 3H balancing choice had a 20/30% chance of success or worse.
But I was surprised.
Instead, from the first simulations, it seems that, at MP, the chances of success are close to 50%.
When it is wrong, the balancer goes for a number, but this is not a big issue at MP.
So I decided to post a few hands for the benefirt of the readers, as these results are quite interesting and they made me think a lot about my previous assumptions.
In particular, I should give credit to those who suggested that balancing is quite a stretch, but not completely foolish at MP.
I may post more hands or send them by email if anyone is interested.
----------------------------------------------------------------------
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#2
Posted 2004-July-18, 15:57
Psyche (pron. sahy-kee): The human soul, spirit or mind (derived, personification thereof, beloved of Eros, Greek myth).
Masterminding (pron. mstr-mnding) tr. v. - Any bid made by bridge player with which partner disagrees.
"Gentlemen, when the barrage lifts." 9th battalion, King's own Yorkshire light infantry,
2000 years earlier: "morituri te salutant"
"I will be with you, whatever". Blair to Bush, precursor to invasion of Iraq
#3
Posted 2004-July-18, 16:19
1eyedjack, on Jul 18 2004, 09:57 PM, said:
I may do that.
I usually use as a criterion for raising a balancer the following:
- with a fit, I raise to game with a 7/7.5-losers hand; with an 8 losers hand the decision is close and I may pass or raise according to "table feel"
- without fit, I raise to NT or major game with a full opening hand.
Balancer assumes I have about 10 hcp (or an 8 losers hand), so he is alreadyt bidding my values.
Therefore I raise only with some extra.
Do you agree with these criteria ?
YThey are the same I am using to evaluate the simulations.
#5
Posted 2004-July-18, 16:32
inquiry, on Jul 18 2004, 10:27 PM, said:
"Dealer" is a free software for DOS/Unix.
You have to create a text file for constraints, you can use one of the example constraints files supplied, change them according to your needs and play with these.
After playing with it for a while, it becomes easy.
If you need some help, message me your email, I'll send you an example file and the basic commands.
In order to run it for DOS, you may need to download from the net also the cygwin1.dll library (any google search will help) and place it in the same folder.
#6
Posted 2004-July-19, 05:15
#7
Posted 2004-July-19, 10:40
#8
Posted 2004-July-19, 10:59
EarlPurple, on Jul 19 2004, 04:40 PM, said:
As I said in the other thread, adding a 7th heart increases the playing strength by about 2 tricks here, it is not a minor change...
However, it may be interesting to move at the other side of the table.
Could you make an example of:
case 1: balancer is a passed hand. Which is the strongest hand that would pass 3H
case 2: balancer is a passed hand. Which is the weakest hand that would raise 3H to game (either 3NT or 4H)
case 3: balancer is a unpassed hand. Which is the strongest hand that would pass 3H
case 4: balancer is a unpassed hand. Which is the weakest hand that would raise 3H to game (either 3NT or 4H)
These kind of examples would be useful for my simulations.
#9
Posted 2004-July-20, 06:46
Clearly it is different from the situation where partner is an unpassed hand. Now it is a lot more difficult, which shows why pre-empts can work.
#10
Posted 2004-July-20, 06:58
EarlPurple, on Jul 20 2004, 12:46 PM, said:
Clearly it is different from the situation where partner is an unpassed hand. Now it is a lot more difficult, which shows why pre-empts can work.
Sure, Earl, but I would like some example hands.
I think balancing need specific requirements in terms of losers (if unvbalanced) or hcp (if balanced); on the basis of these expectations (which may vary from passed and unpassed hand balancing of course), the responder to the balancer may choose whether or not to raise holding a good hand, without having to guess whether pard is broke or if he has a decent playing strength hand (such as the one you suggested with an extra heart).
Otherwise it is always a guess whether to raise a bad balancing or pass a good balancing.
As many say, a bad agreement is better than no agreement whatsoever, if anything because the "no agreement-just judgment" policy tends to bring up "blaming each other" issues; instead if the agreement is fixed (of course with some tolerance for pard's judgment), then the system/agreement may fail, but there is not mutual blaming.
So either balancing is sound, or it is weak, it cannot be both. The definition of "sound" and weak may vary from passed/unpassed hand but it should not vary by more than 2 tricks, I would say.
I believe this is true no matter whether MP or IMPS scoring.
So my question is: what requirements do you suggest(/expect from pard) for raising or passing a passed hand valaancing and an unpassed hand balancing ?
Would you pass pard's balancing with an opening hand and 3 card support if pard is passed or if he is unpassed hand ?
Example hands of the 4 situations I asked in my post will make the point much clearer
Assume Matchpoints scoring.
#11
Posted 2004-July-21, 02:41
3C ??
you normally play pard for 7-8 points. But if it is
3C p p ??
now you usually play pard for an extra king or queen. That is to say, some 9-11 points.
Pard should only raise if he is considerably better than that, say, if he has 13-14 points.. maybe less with compensating distribution.
The situation changes a bit if pard is passed:
p 3C ??
here you can still play pard for 7-8. But you should keep in mind pard is more likely to bid discouragingly than try to show extra values. If it is
p 3C p p
??
since you passed, pard knows you cannot have a good balancing hand, and is therefore less likely to support you, even with a 13-14 hand with moderate fit. He should play you for a hand with around 8-11 points. Such a hand usually has around 8-9 losers, so he should raise you accordingly.
#12
Posted 2004-July-21, 04:20
In IMPs I will only be that concerned about competing the part-score if both 3♣ and 3♥ are making. I may even be prepared to lose 3 imps for taking +50 instead of +140. But I will not want to lose 6 imps for making only +170 if we can make +420 in game. So here I am more likely to come in only if I think my bid will make, and if there is some chance we have game if partner has more than I expected.
#13
Posted 2004-July-21, 05:27
EarlPurple, on Jul 21 2004, 10:20 AM, said:
Earl, I know the difference between MP and IMPS tactics.
What I am asking here is - given the tactics you mention - what are at matchpoints:
- the best hand that should pass a balancing 3H (two cases: by passed and unpassed hands)
- the worse hand that should bid game opposite a balancing 3H (two cases: by passed and unpassed hands)
You say "bid what you can make" but it is unclear what you can make if balancer can have a wide range of strength
So I just think it is good bridge and partnership practice to have precise requirements in these cases, if not for balancer, at least for balancer's responder (not to miss good games and not to bury a light balancer).
Can you give some examples (not general principles- they are generally quite clear) ?
Thanks !
#14
Posted 2004-July-21, 05:32
whereagles, on Jul 21 2004, 08:41 AM, said:
3C ??
you normally play pard for 7-8 points. But if it is
3C p p ??
now you usually play pard for an extra king or queen. That is to say, some 9-11 points.
Pard should only raise if he is considerably better than that, say, if he has 13-14 points.. maybe less with compensating distribution.
The situation changes a bit if pard is passed:
p 3C ??
here you can still play pard for 7-8. But you should keep in mind pard is more likely to bid discouragingly than try to show extra values. If it is
p 3C p p
??
since you passed, pard knows you cannot have a good balancing hand, and is therefore less likely to support you, even with a 13-14 hand with moderate fit. He should play you for a hand with around 8-11 points. Such a hand usually has around 8-9 losers, so he should raise you accordingly.
Ok, thanks whereagles for your contribution.
It is a bit aggressive in my view to balance with 9 losers (even by a passed hand) if pard will raise with 13-14 and a moderate fit, but as long as the partnership is intune, fine.
The reason why I asked this was to run a set of simulations to verify winning and losing decisions by raising or passing the balance.
I will let you know.
Thanks again
#15
Posted 2004-July-21, 06:19
Eagerly awaiting results....