[jdulmage]

While I was directing the Friday Night Non-Life Master game, on board 8, this hand came up.

Scoring: MP

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Most people were playing in 6♦ or 6NT, but nobody seemed to find 7NT.

I have my ways of finding it by opening 2♣ first and once partner with ♦AKQJ10x will bid 3♦ over 2♣ and I'm sure we will get there.

I asked another good player who said he would open 1♣, but I am torn between options.


What would you do? It's your call.

[Rebound]

I can easily see why no one is in the grand. You may have a club or spade loser. Swap the north/south hands and the grand has no play.

[inquiry]

2♣ - 3NT
7NT - pass


I play jump to 3NT show a solid seven card or longer suit, 7NT at worse on a finess after trying to drop the club queen without seeing partners hand.

*whoops,, I miscounted the number of diamonds. With only six diamonds, I would not get to 7NT*

[iscbrooks]

Grand slam is not the correct contract, requiring two successful finesses to make (unless West's small cards are bigger than south's). The fact that it would make here is irrelevant, as it would lose another 75% of the time.

[Free]

Grand is ugly! You need at least 1 finesse to make it...

[jdulmage]

Grands are not avoided when you have to take a single finese. I could see if it relied on two fineses, but one? Out of I think the 12-13 grand slams I have bid in my life, at least 5 of them relied on a finese.


But ok, I guess the "panel" as we will call it would rather play 6NT.

[hrothgar]

jdulmage, on Nov 29 2004, 12:02 AM, said:

Grands are not avoided when you have to take a single finese. I could see if it relied on two fineses, but one? Out of I think the 12-13 grand slams I have bid in my life, at least 5 of them relied on a finese.


But ok, I guess the "panel" as we will call it would rather play 6NT.

Novel concept

Care to explain the math?

In particular, I'd be interested in understanding the expected gain compared to the epxected loss of bidding a 50% grand...

[Free]

Gain & loss of a 50% grand is 0. Same goes for small slams. However, this slam is FAR from 50% imo, as I said, you need at least 1 working finesse... If ♣s are 4-1 you need both finesses to work. If ♣s are 5-0, you'll probably cash the A first and you're screwed again.

[luke warm]

Free, on Nov 29 2004, 12:33 AM, said:

Gain & loss of a 50% grand is 0. Same goes for small slams.

this isn't quite accurate, is it? too many assumptions re: bidding at other tables imo

[daswallow]

7NT is crazy, if it goes down which is quite likely then you lost a load of points.
I'd only bid it if desperate for a good score.

[hrothgar]

Free, on Nov 29 2004, 01:33 AM, said:

Gain & loss of a 50% grand is 0.  Same goes for small slams.  However, this slam is FAR from 50% imo, as I said, you need at least 1 working finesse...  If ♣s are 4-1 you need both finesses to work.  If ♣s are 5-0, you'll probably cash the A first and you're screwed again.

You sure about this???

Assume a NV 50% grand slam in NT

If I bid 6N, my expected score = .5(990) + .5(1020) = 1015
If I bid 7NT, my expected score = .5(-50) + .5(1520) = 735

Looks to me like bidding a 50% grand slam yields an expected loss of 280...

A NV Grand Slam needs to be at least 65.27777% or some such to be worth bidding

[Free]

2 possibilities:

- opps make 3NT+2, you play 6NT-1.
score: 660+100=760 (V) or 460+50=510 (NV)

- opps make 3NT+3, you make 6NT=
score: 1440-690=750 (V) or 990-490=500 (NV)

So the bonus is the same as the loss...

I just realized this is for imps. In MP's I might be wrong.

[cf_John0]

Almost with the dummy hands,it's possible to bid and complete Grand slam.
25% at normal condition.

[Cascade]

hrothgar, on Nov 30 2004, 05:29 AM, said:

Free, on Nov 29 2004, 01:33 AM, said:

Gain & loss of a 50% grand is 0.  Same goes for small slams.  However, this slam is FAR from 50% imo, as I said, you need at least 1 working finesse...  If ♣s are 4-1 you need both finesses to work.  If ♣s are 5-0, you'll probably cash the A first and you're screwed again.

You sure about this???

Assume a NV 50% grand slam in NT

If I bid 6N, my expected score = .5(990) + .5(1020) = 1015
If I bid 7NT, my expected score = .5(-50) + .5(1520) = 735

Looks to me like bidding a 50% grand slam yields an expected loss of 280...

A NV Grand Slam needs to be at least 65.27777% or some such to be worth bidding

This math depends on the method of scoring. If it is total points you are correct.

[Free]

Jlall, on Dec 1 2004, 08:17 AM, said:

at imps you will only want to be in a grand on a hook if

A) you are sure they will be in a small slam at the other table and

B ) you are the weaker team OR
C) you are down in the match and there is not a significant amount of time to make it up.

How can you know what your opps will bid at the other table? Can you see through walls? Do you know ALL your opponents? Doesn't anything strange happen sometimes?

[inquiry]

No you can't see through walls, but if partner opens 1NT (!5-17) and you have 18, you can guess no one will miss small slam.

But it is not this simple. Let's take being vul as an example...

Bit small slam, and make you score 1430. Bid grand slam and make, you score 2210. So what are the risk and rewards when you are right and wrong...

Let;s assume HEarts win 12 or 13 tricks... if you bid the grand, you win by 750 points (2210 versus 1430), or +13 imps. But if you are wrong, you lose by 1530 or 17 imps. Thus if the grand slam is on a finessee, you are risking 17 imps to gain 13, in the long run a losing proposition. Justin's advice however is sound. If you are the underdog or behind late in the match, bidding such a slam is not such bad odds for you to pick up a swing. If you ar behind, bidding the small slam you are still behind, but if it makes, half the time you surge forward, the other half the time? well you were behind already... This has something to do with the theory Kit Woolsey (I think) descibed a couple of decades ago in bridge world as "useful imp theory"

Ben

[PriorKnowledge]

At IMPs, Grand slams are risky. Assuming the small is sure, NVul you risk 14 IMPS if wrong and gain 11 if right. So you need a 56% chance to break even. Vul it is +13 to -17 needing a 57% chance.

At MP, the risk is much higher. In a mixed field several pairs will miss the slam altogether and few will bid the grand. So you risk turning an above average board into a zero in order to turn an above average board into a top. And that does not count the fact that 6 making 7 will garner even more MP if the play for 7 is difficult. In that case, you risk turning an already near top into a zero for almost no extra MP.

A good rule-of-thumb is bid the grand if at worse the grand depends on a finesse.