[barmar]

Lobowolf, on Jun 17 2009, 08:49 PM, said:

Wish I could remember the story and source completely accurately, but my recollection is that it's something to the effect that someone told Barry Crane that when faced with a pure 2-way guess for a queen, he did it differently depending on whether a certain card was in dummy, or in his hand, or something, and wanted Crane's validation. Crane told him it didn't matter as long as he did it the same way each time. As I recall, neither the anecdote nor Crane's comment was presented as being ironic. I'll try to find the excerpt and reference it.

It's like thinking that the long-term expectation on a coin flip depends on picking the same choice every time. Bizarre.

Barry Crane's Rule is that the Queen is over the Jack in a minor, under the Jack in a major. Here's an article by Grant Baze that includes an anecdote about this.

http://www.blakjak.d...o.uk/crane1.htm

If it has any basis in fact, it might have something to do with whether the opponents were more likely to compete with values in a major versus a minor, although I don't see how that relates their holding to the positions of your honors in the two hands. So it's most likely just a superstition, as Grant says.

[se12sam]

I agree with jdonn completely. Having a "rule" save a lot of stress and thought.

I also suspect (but have no way of proving) that Barry Crane's rule may have had some statistical validity in times of manually shuffled / duplicated boards. With the advent of computer dealt truly random hands, the value of the rule is only for peace of mind.

[pdmunro]

jdonn, on Jun 17 2009, 07:40 PM, said:

Free, on Jun 16 2009, 02:58 PM, said:

- Opps get a lot more HCP (which usually results in more total points and money).  I know I've done calculations in the past, and HCP NS vs HCP EW were about equal.  However, if you switch sides now and then, your opps can get way more HCP than average.

Sorry but this comment shows a complete and utter lack of understanding about probability and statistics of any kind. It is equivalent to the following argument.

You and I will both pick a card from each of 100 different decks and whoever picks more aces wins. However, if sometimes you pick first and sometimes I pick first then you can get way more aces than I get, which is not fair.

Do you know what "random" means?

Re the use of statistics:

I don't want to get too off-topic, but I have become interested in reading the ideas of W. Edwards Deming whose aim was to improve the quality of manufactured products in Japan and the USA. My paraphrase of his central thesis is that it is not really relevant to just pick a random sample of manufactured products and test their quality.

What is needed is a sampling along a time line. There will always be variabilty in the manufactured product. This is completely unavoidable and needs to be recognized as such. It is due to 1001 interactions that are part of any process.

What is important is that both the long-run performance and natural variabilty are determined and then monitored continuously. If it is observed, for any series of continuous time points, that the performance is consistently above or below the long-term average, management needs to recognize that special factors are at work and adopt remedies to return the process to its long-term average.

What has this to do with bridge? Maybe it's relevant to Free's concerns, maybe not.

But the key tenet of Deming is out there: Don't always think in terms of a simple average, there is a time component to events that we ignore at our peril.

In my own case, I know I try to monitor my alertnes before I play on BBO. I sometimes do this by playing a couple of hands on Bridge Baron. I am testing whether my brain is too tired to think, or not, as tiredness is the special factor that most often prevents me from performing at my true level.

In summary, I am just trying to keep my mind open to Deming's ideas. They are credited with playing a key role in the miracle that is modern Japanese manufacturing. I think they must have relevance in other fields, such as bridge and education, my key areas of interest.

[gnasher]

se12sam, on Jun 18 2009, 10:46 AM, said:

I also suspect (but have no way of proving) that Barry Crane's rule may have had some statistical validity in times of manually shuffled / duplicated boards. With the advent of computer dealt truly random hands, the value of the rule is only for peace of mind.

The rule that the queen lies over the jack comes from rubber bridge. You're more likely to play the queen on the jack than the jack on the queen. Thus the queen will tend to be immediately above the jack when the cards are face up, immediately below the jack when the cards are face down, and immediately over the jack when the cards are redealt.

The same applies at duplicate, for a different reason. When leading touching honours most people would lead the queen and then the jack. Again, the queen will end up under the jack with the cards face down, and over the jack when they're redealt.

This may change if there are lots of early claims. When sorting their hands, most people put the high cards behind the low cards. If a queen-jack combination is unplayed at the end of the hand, the queen will be redealt in front of the jack.

Naturally, none of this applies when the hands are randomly dealt. If I didn't know better, I'd say that anyone who seriously believed that this rule applied to computer-dealt hands was an idiot.

[gnasher]

pdmunro, on Jun 18 2009, 01:00 PM, said:

What has this to do with bridge? Maybe it's relevant to Free's concerns, maybe not.

But the key tenet of Deming is out there: Don't always think in terms of a simple average, there is a time component to events that we ignore at our peril.

It's relevant only if you think that the dealer might have a systemic bias that varies with time. It seems unlikely that BBO's developers would have made such an error.

[Free]

jdonn, on Jun 18 2009, 01:40 AM, said:

Free, on Jun 16 2009, 02:58 PM, said:

- Opps get a lot more HCP (which usually results in more total points and money).  I know I've done calculations in the past, and HCP NS vs HCP EW were about equal.  However, if you switch sides now and then, your opps can get way more HCP than average.

Sorry but this comment shows a complete and utter lack of understanding about probability and statistics of any kind. It is equivalent to the following argument.

You and I will both pick a card from each of 100 different decks and whoever picks more aces wins. However, if sometimes you pick first and sometimes I pick first then you can get way more aces than I get, which is not fair.

Do you know what "random" means?

Sorry but you'd be surprized of my understanding of probability. However I believe you forgot 1 important word in my sentence ("can") and my remark at the bottom of my post. I didn't say it's so in the long run (that would be foolish), and playing about 10 boards each time makes a huge difference since there's more variance. If I'd play 1000 boards I would have a better chance to reach the obvious average of 20HCP.

Your example is completely not equivalent. The one with the coins however is a lot more relevant.

I looked up my previous post where I used REAL data to show what I'm talking about:
http://forums.bridgebase.com/index.php?sho...ndpost&p=276799
You'll see that there a big difference between the average NS/EW and the average myside/oppsside in this session.

Obviously, if you'd keep the seats fixed, you'll have sequences of boards where 1 side gets more HCP than the other side. So it won't change much. However, for me it's frustrating that you're sitting EW for a few hands and don't get much HCP, suddenly you switch sides and the HCP also switched sides so the series of bad boards continues.

If you'd look at ALL the hands I've played in moneybridge (not just the ones in 1 session) I'll probably have around 20HCP each time (which is statistically correct), but the fun of one session can go away pretty quickly if your side keeps getting very few hcp. Since I play pretty short sessions, this factor is quite important for me.

[Lobowolf]

Free, on Jun 18 2009, 01:17 PM, said:

jdonn, on Jun 18 2009, 01:40 AM, said:

Free, on Jun 16 2009, 02:58 PM, said:

- Opps get a lot more HCP (which usually results in more total points and money).  I know I've done calculations in the past, and HCP NS vs HCP EW were about equal.  However, if you switch sides now and then, your opps can get way more HCP than average.

Sorry but this comment shows a complete and utter lack of understanding about probability and statistics of any kind. It is equivalent to the following argument.

You and I will both pick a card from each of 100 different decks and whoever picks more aces wins. However, if sometimes you pick first and sometimes I pick first then you can get way more aces than I get, which is not fair.

Do you know what "random" means?

Sorry but you'd be surprized of my understanding of probability. However I believe you forgot 1 important word in my sentence ("can") and my remark at the bottom of my post. I didn't say it's so in the long run (that would be foolish), and playing about 10 boards each time makes a huge difference since there's more variance. If I'd play 1000 boards I would have a better chance to reach the obvious average of 20HCP.

Your example is completely not equivalent. The one with the coins however is a lot more relevant.

I looked up my previous post where I used REAL data to show what I'm talking about:
http://forums.bridgebase.com/index.php?sho...ndpost&p=276799
You'll see that there a big difference between the average NS/EW and the average myside/oppsside in this session.

Obviously, if you'd keep the seats fixed, you'll have sequences of boards where 1 side gets more HCP than the other side. So it won't change much. However, for me it's frustrating that you're sitting EW for a few hands and don't get much HCP, suddenly you switch sides and the HCP also switched sides so the series of bad boards continues.

If you'd look at ALL the hands I've played in moneybridge (not just the ones in 1 session) I'll probably have around 20HCP each time (which is statistically correct), but the fun of one session can go away pretty quickly if your side keeps getting very few hcp. Since I play pretty short sessions, this factor is quite important for me.

ok, but there's no difference in your expectation, for a session of any duration, whether you're N/S every time, E/W every time, alternate every hand, or play N/S twice followed by E/W seven times, then N/S twice again.

Yes, the short-term swings can be quite disparate, but a priori, there's no seating sequence at all that would give you any different likelihood of getting more points, fewer points, or an average amount of points as compared with any other seating sequence.

[TimG]

Free, on Jun 16 2009, 02:58 PM, said:

- Opps get a lot more HCP (which usually results in more total points and money).  I know I've done calculations in the past, and HCP NS vs HCP EW were about equal.  However, if you switch sides now and then, your opps can get way more HCP than average.
Suppose you distribute HCP NS-EW every round as follows: 25-15, 15-25, 25-15,...  In the long run, NS and EW will have the same amount of HCP.  However, if you also switch sides every round, then your team may get 15HCP on average, while opps get 25 on average!

Are you saying that there is a difference in average HCP held depending upon whether you are always south or switch back and forth between south and west? That the seat switching changes the variance of HCP held?

I'm sure you will agree that the expected HCP are the same whether you stay in the same seat or switch. And, that the expected variance (in any set of X boards) is also the same regardless of position.

So really, the only problem with switching seats is a perception that the "cold streaks" are somehow following you. This is really the same sort of thinking as watching a flipped coin come up heads three times in a row and thinking that it must be "due" for a tails.

[Free]

Indeed. However, I've also had "hot streaks" so it cancels out. My point is that the streaks aren't as pleasant as having a tight game. Long term statistics are irrelevant for the "fun factor".

[jdonn]

Free, on Jun 18 2009, 01:17 PM, said:

Sorry but you'd be surprized of my understanding of probability.

After reading the rest of your post, I would be. Where you sit has nothing to do with your short term streaks, long term streaks, variance, average, or anything else. All it impacts is your own superstition.

Quote

However, for me it's frustrating that you're sitting EW for a few hands and don't get much HCP, suddenly you switch sides and the HCP also switched sides so the series of bad boards continues.

This sums up everything. That frustration is entirely illogical. You can be frustrated that you altogether had a very long streak of bad hands, but if you equate that in any way to the directions you were sitting then you are wrong.

[awm]

You seem to be implying that points come in "runs" (i.e. that there will be a bunch of hands where N/S has more points followed by a bunch of hand where E/W has more points) -- this happens sometimes but really each hand is independent from the last and it's pure random chance.

You could easily have a tourney where you sit N/S the whole time and get no points each hand, whereas if you had switched to E/W halfway through you'd have good hands for the second half. This is just as likely as a tourney where N/S has "the points" for the first half and E/W has "the points" for the second half.

I suppose there is some psychological effect (but not a real one).

The vulnerabilities on the other hand are an issue. If you play a tourney where you are NV for more than half the hands, your ability to score total points is substantially reduced. Of course, it does average out (mean is the same) but swapping vulnerability at random CAN increase the variance.

[Jlall]

As long as you're east you can't lose basically.

[cherdanno]

To avoid the bad streaks, you should walk once around your PC after every hand. This has the same effect as changing seats.

[mtvesuvius]

cherdanno, on Jun 18 2009, 05:37 PM, said:

To avoid the bad streaks, you should walk once around your PC after every hand. This has the same effect as changing seats.

Mine is against a wall, what should I do?

[barmar]

gnasher, on Jun 18 2009, 08:31 AM, said:

se12sam, on Jun 18 2009, 10:46 AM, said:

I also suspect (but have no way of proving) that Barry Crane's rule may have had some statistical validity in times of manually shuffled / duplicated boards. With the advent of computer dealt truly random hands, the value of the rule is only for peace of mind.

The rule that the queen lies over the jack comes from rubber bridge. You're more likely to play the queen on the jack than the jack on the queen. Thus the queen will tend to be immediately above the jack when the cards are face up, immediately below the jack when the cards are face down, and immediately over the jack when the cards are redealt.

But why would the position of the queen be different for majors versus minors? That's what Barry Crane's rule is about.

[xcurt]

For those playing a lot of bbo moneybridge, how well does GIB play? How much better does is play if you give it more cpu (Uday or Fred?). Is it the best computer program? I tried wbridge5 since it's free and it's hopeless, I cannot believe it honestly won the computer world championship once or twice, it was so bad I'm not going to pay money to try Jack if Jack lost to it on the computer worlds.

I'm not interested in playing with the computer, I'm interested in writing a bridge program btw.

[cherdanno]

GIB's card play is very good. It does have some weirdnesses, e.g. it often removes guesses for you.

[hanp]

Free, on Jun 18 2009, 01:17 PM, said:

jdonn, on Jun 18 2009, 01:40 AM, said:

Do you know what "random" means?

Sorry but you'd be surprized of my understanding of probability.

Please surprise us!

[gnasher]

barmar, on Jun 18 2009, 11:41 PM, said:

But why would the position of the queen be different for majors versus minors?  That's what Barry Crane's rule is about.

I don't know. The rule I stated has been around for ages. The Encyclopedia of Bridge credits it to a Clagett Bowie, who was born twenty years before Barry Crane.

Maybe Crane decided that applying this rule to computer-dealt hands wasn't sufficiently irrational, so he added an extra absurdity?

[P_Marlowe]

Free, on Jun 18 2009, 01:17 PM, said:

<snip>
I looked up my previous post where I used REAL data to show what I'm talking about:
http://forums.bridgebase.com/index.php?sho...ndpost&p=276799
You'll see that there a big difference between the average NS/EW and the average myside/oppsside in this session.

Obviously, if you'd keep the seats fixed, you'll have sequences of boards where 1 side gets more HCP than the other side.  So it won't change much.  However, for me it's frustrating that you're sitting EW for a few hands and don't get much HCP, suddenly you switch sides and the HCP also switched sides so the series of bad boards continues.

If you'd look at ALL the hands I've played in moneybridge (not just the ones in 1 session) I'll probably have around 20HCP each time (which is statistically correct), but the fun of one session can go away pretty quickly if your side keeps getting very few hcp.  Since I play pretty short sessions, this factor is quite important for me.

This is a real observation and can be proven mathematically.

Simply put: If you are on the loosing side, the probability that
you will stay on this side is higher and growing over time.
The probability that the score will be +-0 will go too zero, if time
goes on, if I remember it correct even with exponenatial speed.

But switching sides has nothing to do with it and wont change
anything at all, only a reset will.

With kind regards
Marlowe