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Grands at IMPs?

#1 User is offline   billw55 

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Posted 2010-July-06, 07:23

In general, how much of a favorite do you want a grand slam to be to bid it in a team game - as opposed to stopping in six. Would you bid a grand that you figure is 60% to make? How about 70%, 80%, or 90%? Is there a significant difference between vul and nonvul?

Are there any stats out there on the rate of making grands versus going down in high level team competition? For example, in Vanderbilts, Bermuda Bowls, etc.
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#2 User is offline   pooltuna 

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Posted 2010-July-06, 07:57

billw55, on Jul 6 2010, 08:23 AM, said:

In general, how much of a favorite do you want a grand slam to be to bid it in a team game - as opposed to stopping in six. Would you bid a grand that you figure is 60% to make? How about 70%, 80%, or 90%? Is there a significant difference between vul and nonvul?

Are there any stats out there on the rate of making grands versus going down in high level team competition? For example, in Vanderbilts, Bermuda Bowls, etc.

This is just a number crunching problem and not having done it in a while I seem to recall the grand had to make about 80% of the time on the assumption that opps stopped in a making small slam. Of course you could just use Hudecek's rule which basically says never bid 7 unless you can count 14 tricks ;)
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#3 User is offline   Stephen Tu 

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Posted 2010-July-06, 08:16

No, it's not 80% if you are SURE the other team got to at least small. It's only 56-57% depending on vul.

Giving room for accidents at the other table, generally you want to bid the grand if you know it's just on a 3-2 break, or if the bidding tells you that it's close to a tossup between 100% cold and being on a hook (so on average ~70+%).

Avoid bidding marginal grands on low HCP against inferior teams.
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#4 User is offline   hanp 

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Posted 2010-July-06, 08:35

What Stephen said.
and the result can be plotted on a graph.
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#5 User is offline   kfay 

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Posted 2010-July-06, 08:41

There was some article that said, theoretically speaking, that the probability need to be >=2/3 the probability that the small will make.

In actuality... you gotta be pretty sure ;)
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#6 User is offline   billw55 

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Posted 2010-July-06, 09:04

Interesting. As you might have guessed, there is a story behind this.

I held:

♠AQJT963
♥AKJ8
♦A
♣A

After three passes, the auction goes:

2♣ - 2♦ (gf)
2♠ - 3♠ (extras)
4NT - 5♣ (1 key)

At this point I thought the grand was a pretty good bet so I went ahead and bid 7♠. Perhaps I could have asked about kings. A trump was led and partner tabled:

♠K54
♥xx
♦Jxxxx
♣Jxx

As you can see, there was a miscommunication and partner did not actually have extras. Despite this, the fortunate heart doubleton allowed me to make it. We won 13 IMPs versus the small slam at the other table.

After the game, my LHO (a clearly better player than I) approached me and offered some advice: you should not bid this grand, it was not safe, you were lucky to make it. Which was true on the actual hand - but on the auction I thought the chances were pretty good. Anyway, her advice was that one should only bid a grand at IMPs if you can count 13 tricks. On the grounds that if you go down, it could lose the match for your team. The conversation accumulated several other lurkers, and all of them (including my own partner) agreed with her. I failed to understand, offering that while yes this bid could lose the match, it could also win the match, and was in fact a favorite to do so. But this line of thought was rejected all around.

I even offered a list of reasonable chances to make 7, considering that partner showed extras. Partner could hold:

♥Q
short ♥
both minor suit kings
KQ of either minor
QJT of either minor, ruffing finesse works

and also:

♥Q drops
♥Q onside (OK I can't try both of these)
opps lead ♥

I figured all this puts the grand around 80%. The response to this was "you should never bid a grand on a finesse".

;)
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#7 User is offline   kfay 

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Posted 2010-July-06, 09:11

Sounds like this woman isn't actually all that good
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#8 User is offline   gwnn 

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Posted 2010-July-06, 09:13

billw55 1-0 unknown expert

or should I say 13-0 at imps ;)
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#9 User is offline   Stephen Tu 

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Posted 2010-July-06, 09:17

It would be good to simply have methods to ask about 3rd round control of hearts (with partners whom I've discussed this with, 6♥ after keycard or a queen ask does this).

I also prefer methods where one can distinguish between real slammish positive (say K +K + Q min, or A+K), and semi-positive (~4-7, GF but not really slam invite opposite min 2♣ opener).

It seems wasteful to always have to jump to game with a "minimum" GF, although if it was defined as a hand like responder's, no side controls, that would be OK.
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#10 User is offline   billw55 

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Posted 2010-July-06, 09:24

Stephen Tu, on Jul 6 2010, 10:17 AM, said:

It would be good to simply have methods to ask about 3rd round control of hearts (with partners whom I've discussed this with, 6♥ after keycard or a queen ask does this).

I also prefer methods where one can distinguish between real slammish positive (say K +K + Q min, or A+K), and semi-positive (~4-7, GF but not really slam invite opposite min 2♣ opener).

It seems wasteful to always have to jump to game with a "minimum" GF, although if it was defined as a hand like responder's, no side controls, that would be OK.

Interesting stuff. My bidding isn't that advanced yet. What is a queen ask after keycard?
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#11 User is offline   MickyB 

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Posted 2010-July-06, 09:26

People tend to be very risk averse in some situations. People often take actions with the intention of flattening boards when there's no reason to do so*, I think this is similar.

I guess this is partly down to psychology too - the feeling from having been the person who "won the match" is usually less intense than the feeling from having been the person who "lost the match".

* Valid reasons include "we were winning with only a few boards left" and, to a lesser extent, "we are a better team than the opposition".
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#12 User is offline   billw55 

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Posted 2010-July-06, 09:36

MickyB, on Jul 6 2010, 10:26 AM, said:

People tend to be very risk averse in some situations. People often take actions with the intention of flattening boards when there's no reason to do so*, I think this is similar.

I guess this is partly down to psychology too - the feeling from having been the person who "won the match" is usually less intense than the feeling from having been the person who "lost the match".

* Valid reasons include "we were winning with only a few boards left" and, to a lesser extent, "we are a better team than the opposition".

Yes, my LHO mentioned that. This occurred on the third board of a six board match. The first two were partscores, I didn't really think much was happening there. But apparently she suspected we were already ahead. Which turned out true, we gained I think 6 IMPs on the first two boards. So she was right that it was an unnecessary risk in context of the match score. Which I would certainly agree with - if I knew the score. Clearly, she was better at estimating IMPs than I. For this and many other reasons, I know that she knows what she is talking about, and is not any sort of "fake expert".

As for a stronger team, the opps at my table were definitely stronger than us, but at the other table weaker than our teammates (it was an 8 is enough game). So on balance it seemed like a more or less even matchup.
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#13 User is offline   655321 

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Posted 2010-July-06, 09:37

billw55, on Jul 6 2010, 10:04 AM, said:

The response to this was "you should never bid a grand on a finesse".

Explain to her that this is just another way of saying "don't bid 50% grands", and that you considered the extra chances brought the odds to more than 60% or so, and made seven worth bidding.

If that doesn't work, show her the IMP column on your scoresheet.
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#14 User is offline   neilkaz 

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Posted 2010-July-06, 09:44

kfay, on Jul 6 2010, 10:11 AM, said:

Sounds like this woman isn't actually all that good

Agreed and nice bid, Bill55 after partner shows extras.

Methods to ask for a 3rd rd ♥ control would be nice, but for now, more important to discuss with partner what hand has extras on the sequence and what hand jumps to 4♠ where I agree with Steven that this should show a min and no outside controls (dub♥ not a control)
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#15 User is offline   mikeh 

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Posted 2010-July-06, 09:44

Kaplan used to say that one should figure the grand to be 75% or better. And he was frequently analyzing very high level matches...his point being that even good pairs have accidents and miss slam completely on enough boards that the comparison is not (universally) between small and grand. Sometimes, even on seemingly routine boards, bidding a cold small slam wins imps.

I suppose that if you knew that your counterparts used the same methods as you did, and that your hand fell squarely in the middle of range for your bids, such that the auction was almost certainly going to be duplicated at the other table, you could start shading this 75% figure....but bidding has become so non-standardized these days that it is a rare hand on which both pairs in a team match have identical auctions.

As for the OP: the answer to the woman who thought she was an expert is that it is one thing to say: never bid a grand on a finesse (a statement with which I agree unless you are stuck) and a completely different thing to say: never bid a grand that is going to be no worse than a finesse.

As the OP pointed out, in a later post, he had many possible dummies, on his auction, that would have rendered the grand frigid....and he could tell that the grand was probably no worse than a finesse (yes, I know one can construct layouts where it needs a little more, but one really has to stretch).

My own view, against a team that I respect, is that if I can count 12 tricks and I know on the auction that we have something in reserve...if I know that it is at worst on a finesse and that it may well be cold...I bid it...so long as the 'may well be cold' doesn't feel like a stretch.
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#16 User is offline   bid_em_up 

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Posted 2010-July-06, 10:58

Mike,

Should the above vary based upon the length of the match? In a short match (i.e. six boards), I would expect that it would need a higher percentage of success in order to actually bid the grand.

Yes? No?
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#17 User is offline   Phil 

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Posted 2010-July-06, 11:16

bid_em_up, on Jul 6 2010, 11:58 AM, said:

Mike,

Should the above vary based upon the length of the match? In a short match (i.e. six boards), I would expect that it would need a higher percentage of success in order to actually bid the grand.

Yes? No?

Why would you think this matters?
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#18 User is offline   hanp 

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Posted 2010-July-06, 11:17

If you want to maximize your VP expectancy in short matches then I think you should bid grands a bit more aggressively. I also think that it is a waste of time thinking about it.

To Phil: why do you think it does not matter?
and the result can be plotted on a graph.
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#19 User is offline   peachy 

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Posted 2010-July-06, 11:25

billw55, on Jul 6 2010, 10:04 AM, said:

Interesting. As you might have guessed, there is a story behind this.

I held:

♠AQJT963
♥AKJ8
♦A
♣A

After three passes, the auction goes:

2♣ - 2♦ (gf)
2♠ - 3♠ (extras)
4NT - 5♣ (1 key)

At this point I thought the grand was a pretty good bet so I went ahead and bid 7♠. Perhaps I could have asked about kings. A trump was led and partner tabled:

♠K54
♥xx
♦Jxxxx
♣Jxx

As you can see, there was a miscommunication and partner did not actually have extras.

Your bidding was fine, your partner's isn't, IMO. Responder definitely does not have extras, he has a a rock bottom minimum for what he has promised. I think you are allowed to expect two kings for "extras".
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#20 User is offline   ArtK78 

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Posted 2010-July-06, 11:31

You never know what is going to happen at the other table.

I have told this story before.

In the last round of a Swiss Teams, with the event on the line, my partner and I had a disaster on a reverse auction. He thought he used a sequence that was game forcing and a slam try, I thought he was using a sequence that was a sign off. We played in 3♦. There were 12 top tricks, and 13 as long as diamonds were not 4-0 in LHO's hand.

They were.

At the other table, our opps bid to the excellent grand.

We won 6 IMPs - +170 and +50.
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