[serapuff]

Hi,

Does anyone know the odds of making 3NT with a 6-2 fit and 23 hcp exactly? Will it be more or less than 50%?

Thanks!
Gideon

[OleBerg]

No. Nobody knows that.

[gnasher]

The best way to find out is to bid it and see if it makes.

[Cascade]

gnasher, on Jun 9 2010, 09:27 PM, said:

The best way to find out is to bid it and see if it makes.

That will not tell you the odds.

[cherdanno]

Cascade, on Jun 9 2010, 06:03 AM, said:

gnasher, on Jun 9 2010, 09:27 PM, said:

The best way to find out is to bid it and see if it makes.

That will not tell you the odds.

You just need to do it often enough.

[foo]

serapuff, on Jun 9 2010, 01:35 AM, said:

Hi,

Does anyone know the odds of making 3NT with a 6-2 fit and 23 hcp exactly? Will it be more or less than 50%?

Thanks!
Gideon

No one can tell you exact odds unless we are talking about a specific board.

However, your 2nd question can be answered in general.

If you want to be in a > 50% 3N, usually (there ARE exceptions!) it takes
26+ HCP if we do not have an 8+ card fit between the 2 hands, and
25+ HCP if we DO have an 8+ card fit between the 2 hands.

There is also a known effect where it takes less HCP overall the more evenly those HCP are distributed between Declarer and Dummy.

To the point where if there is exactly 12 HCP in each hand= 24 HCP total, 3N is usually > 50%.

The reverse is also true. The greater the disparity in strength between the two hands, the more total HCP we need to have for a > 50% chance of making 3N.
(If you think about the transportation issues implied by one hand or the other having much fewer HCP, this should make sense intuitively.)

You will usually expect to be -1 in 3N if you only have 23 HCP between you.

Most of the exceptions where you make 3N with less values than the above guidelines will involve having a solid or semi-solid source of tricks (AKQxxx, KQJxxx, etc) +and+ stoppers in all the side suits.
When you have such lucky circumstances, you can often make 3N with far fewer HCP than the usual amounts.

[gwnn]

And have a good enough memory. Some of our posters are, judging by their avatars, goldfish or other species of fish.

OH!! WELCOME BACK FOO!

[rhm]

A simulation (1000) deals assuming both hands are at least semi balanced (but no other constraints like suit quality, intermediates, distribution of points between declarer and dummy etc.) shows a success rate double dummy of 32%.
In practice (single dummy) it is likely to be slightly higher but not by very much, certainly below 40%.

Rainer Herrmann

[Free]

With super computers you might be able to give an exact number, but your parameters are so general that I'd say something like 25%. It depends on the suit quality, location of honours, having all suits stopped,...

[foo]

gwnn, on Jun 9 2010, 06:55 AM, said:

OH!! WELCOME BACK FOO!

Thanks!

[dake50]

Yes, more than 50%. In fact, the linear interpolation for 50% is 22.3 hcp.

[pooltuna]

serapuff, on Jun 9 2010, 01:35 AM, said:

Hi,

Does anyone know the odds of making 3NT with a 6-2 fit and 23 hcp exactly? Will it be more or less than 50%?

Thanks!
Gideon

This is usually a suit quality issue. J65432 vs Q7 I wouldn't like my chances but AKT432 opposite Q5 rates to only require 3 side suit tricks.

[serapuff]

A simulation (1000) deals assuming both hands are at least semi balanced (but no other constraints like suit quality, intermediates, distribution of points between declarer and dummy etc.) shows a success rate double dummy of 32%.
In practice (single dummy) it is likely to be slightly higher but not by very much, certainly below 40%.

Rainer Herrmann

This was what I was looking for.

Thanks!
Gideon

[Cascade]

With these constraints:

spades(north)==6 and
spades(south)==2 and

# It would be the same for any other 6=2 fit

hcp(north)+hcp(south)==23

I got these frequencies for the number of tricks one in 1000 deals double dummy

0 0
1 0
2 0
3 4
4 21
5 55
6 126
7 233
8 298
9 184
10 64
11 15
12 0
13 0

Eliminating some of the silly cases by forcing both hands to be resonably balanced - 6322 in the hand with the six card suit and 4432, 5332, 5422, 6322 or 7222 in the hand with the doubleton - the numbers became:

0 0
1 0
2 0
3 4
4 9
5 46
6 128
7 251
8 291
9 186
10 74
11 8
12 3
13 0

These numbers are considerably lower than the simulation by Rainer.

Here is my code:

spades(north)==6 and
spades(south)==2 and

shape(north, any 6322) and
shape(south, any 4432 + any 5332 + any 5422 + any 6322 + any 7222) and

hcp(north)+hcp(south)==23

with the reporting statement being

frequency (tricks(south,notrumps),0,13),

[cloa513]

The original question is too vague- what sort of hand holding 6 cards- balanced or semibalanced (singleton honour) or any. Same question for the hand holding 2 cards. Also is it 3NT solid contract or in all probability given any lead?
The only solid 3NT hands that will make it against reasonable play are all four aces in the partnership and totally running 6 card suit. The 6 carder needs to have an outside ace if partner blocks his suit. Semibalanced except a useless J or singleton ace against any lead can't make.

[serapuff]

I guess I meant in a simulation with the only constraints being a 6-2 fit and 23 hcp combined, what is the probability of gaming 3NT double dummy.

[jjbrr]

50-50. you either make it or you dont.

[dake50]

pooltuna nailed this one.
Are you asking "undefined and un-shown (partner didn't announce this suit)" 6-suit?
Or given a AK,AQ,KQxxxx shown, or known?
The good 6-suit opposite Tx(+) is a very likely 6 tricks needing 3 from the 13 hcp not 6-suit AKQ in 22 combined. Is that the question?

Try: Goren 26 with 4-4, or 5-3 fit is 26.
What to add for good 5-suit: expected AKQ? Some plus for 12w12, near 24.
What for good 6-suit: expected AKQ? Near 22.

[matmat]

dake50, on Jun 9 2010, 11:10 PM, said:

pooltuna nailed this one.
Are you asking "undefined and un-shown (partner didn't announce this suit)" 6-suit?
Or given a AK,AQ,KQxxxx shown, or known?
The good 6-suit opposite Tx(+) is a very likely 6 tricks needing 3 from the 13 hcp not 6-suit AKQ in 22 combined. Is that the question?

Try: Goren 26 with 4-4, or 5-3 fit is 26.
What to add for good 5-suit: expected AKQ?  Some plus for 12w12, near 24.
What for good 6-suit: expected AKQ?                                            Near 22.

No, he really didn't.

Why are you trying to mangle the original question?

given ANY 23HCP AND exactly a 6-2 fit AND double-dummy defence and play, what fraction of NT contracts make 9 or more tricks?

there are no suit quality conditions, there are no side suit conditions, there are no what ifs, what buts or whatevers.

[cloa513]

By the way anyone want to guess how calculations would be needed to work out the original question? Would you say trillions? 10^12