[AL78]

 helene_t, on 2020-December-08, 04:02, said:

Old bridge books, even otherwise good books, are full of this kind of probability nonsense. The anti-science movement is nothing new. Old reactionaries of my own generation like to blame it on the internet, but truth is that we were even more stupid before we got computers.

Today there's no excuse since you can just google/simulate/wolframalpha the correct probabilities, but even Culbertson didn't have a good excuse, he could just have read Borel's book.

The problem is, people with strong opinions will use Google to find references that support their opinions, and ignore anything that contradicts them, and you can find anything to support an opinion if you look hard and for long enough.

One of the things I much appreciate on this forum is the apparent objectivity when it comes to bridge related questions. If I post a hand up where I got a poor result, if it was my fault, people will tell me and suggest what I should have done, but they will also tell me if I'm unreasonably blaming myself. In other words, there appears to be no bias, just objective analysis.

[pilowsky]

Interestingly in SImon's book it says:


I'm pretty sure there are other reasons why I always lose.

[Lovera]

 pescetom, on 2020-November-29, 15:14, said:

No I had not read this 1954 attempt at self justification, thank you. I shall do so.

I did read and cite the actual article from 1933 that stirred up the whole embarassing mess however, and that is what I am talking about.
It makes no reference to dealing or modification of probability, to mention a couple of terms I glimpsed in your article.

The two articles are related: the first comes from Culbertson's book and concerns the Law of Symmetry while the second confirms the Blackwood Theory, i.e. when to make an impasse or when to play A and K (this depends on how the more short suit is distributed between the two hands).(Lovera)

[Lovera]

 pescetom, on 2020-November-28, 09:52, said:

You are right. To quote from a 1933 newspaper article by Ely Culbertson:
"It was original with me, and I have long recommended it to all bridge players because I know how valuable it has been to me, and thus can be to them. The player must simply remember that whatever the pattern of any hand of 13 cards dealt, there will probably be a suit pattern which corresponds to it. Thus if a player's hand is divided five-four-three-two-one(sic), the distribution of some suit in the four hands will probably be five-four-three-one also. This varies, of course, but only to the extent of one card. That is, the equivalent suit may be divided five-four-two-two."

Almost one hand in four is either 5431 or 5422, so allow space for "exceptions" and this "law" might be seen to work.

This I believe I have personally tested to be true (reversing the assumption and finding where it works) and should relate to perfectly "mirror" hands or similar to this ones by varying only one card such as i.e. 5-4-3-1 or 5-4-2-2.

[P_Marlowe]

 pilowsky, on 2020-December-21, 22:37, said:

Interestingly in SImon's book it says:


I'm pretty sure there are other reasons why I always lose.

This is a statement I recall as well, but ..., I think he used this one
as tie breaker in a situation, when the decision was roughly equal.
And he said, it stops him from thinking to long about a certain situation,
which has no real hope of achieving anything.

[mycroft]

And there was possibly something in it back in the day with "imperfect shuffling". Complete bunk, of course, with computer dealing.

I play (what I remember of) Barry Crane's rule on guessing queens for the same reason, saves brain power on complete guesses. Only, of course, when it *is* a complete guess (or at least a complete guess to me).

[smerriman]

 mycroft, on 2021-December-15, 10:22, said:

I play (what I remember of) Barry Crane's rule on guessing queens for the same reason, saves brain power on complete guesses. Only, of course, when it *is* a complete guess (or at least a complete guess to me).

Heh. Had to look this one up and found the story at the bottom of here. That's pretty funny

[mycroft]

Yeah, I was thinking of the same story when I added that second line...

[pescetom]

 smerriman, on 2021-December-15, 13:24, said:

Heh. Had to look this one up and found the story at the bottom of here. That's pretty funny

It's great
Our defence against multi is not dissimilar in terms of perceived effectiveness vs. mathematical sense.
I guess most of us get by in life following some "rules" we know are actually arbitrary or even worse...
as Woody Allen put it, "we need the eggs!".

[akwoo]

The correct rule on guessing queens is that LHO (who was on opening lead) has it, because that's why they didn't lead the suit.

[Lovera]

 akwoo, on 2021-December-15, 18:26, said:

The correct rule on guessing queens is that LHO (who was on opening lead) has it, because that's why they didn't lead the suit.

In fact it is so and the Law of Symmetry applies perfectly (it can also be read in another way). What Crane's recounted seems to refine what was said in Simon's book, namely that an imperfect shuffling leads to attributing the Queen over the Knave. However, to have a perfect shuffling it is necessary to use the so-called "American" cutting method seven consecutive times.

[bluenikki]

 hrothgar, on 2020-November-28, 07:09, said:

Yes

It is trivial to demonstrate that this is complete nonsense for either

A. Computer dealt hands or
B. Hands that a hand shuffled in "good" manner

It is possible that there is some truth for this for hands that are manually shuffled using some "poor" technique. The problem here is that almost any claim is consistent with bad shuffling.

The only way to really analyze this is to collect all sorts of data about hands that are manually shuffled in bridge clubs and use this to test the hypothesis. There was a data set that got posted a few months back from one bridge club in the Netherlands. As I recall, it didn't show anything particularly interesting.



The issue here is not the complexity of the game, but rather the availability of the data

Easley Blackwood had a theory that if the declaring side had a singleton, the defending side was likely to have one. Mainly this was applied to 9-card fits.

He claimed that he had researched all published world championship deals. When computer dealing was in effect, the rule failed. But he claimed that when manual dealing was employed,it worked.

Carl