[bluejak]

Cascade, on Feb 23 2010, 08:06 AM, said:

I think flatter etc is less random.  In the sense of less haphazard.

I would be very surprised if I was the only one to think this way.

Well, I have to agree with Wayne occasionally!

Yes, I agree.

[helene_t]

Maybe it is a question of semantics, but IMHO if "less random" is to mean anything, then every distortion of the fair distribution (the one that makes every possible deal equally likely) is "less random". Formally, "randomness" could be defined as entropy, i.e. the sum of p*log(p), where p is the probability of particular deal.

So I agree with Wayne.

[mycroft]

As a cryptographer, I agree with <strike>Wayne</strike> Helene. Perfectly random is defined as p(deal X) = p(deal Y) for all X, Y; if some deals have a higher chance of being produced (the "flatter" ones), it's by definition less random.

In Bridge, it's actually an issue: if one knows that hands are skewed to the flatter end (more than, by sheer probability, they will be), it is sensible to build bidding systems around that fact, and to skew the card combination odds to reflect it. One will have fewer unbiddable or "least lie" hands that way; one will make more contracts that way. One will hate "those damned computer hands", though, because system, and play judgement, is now inferior to all the "true" systems that are inferior at the club. Please note, I strongly believe that 20 years ago, this actually was the case (without any intent; the "invisible hand" of the market, so to speak), at least outside the full-time tournament play set.

Interestingly enough, enough people in my area know about the "moar shuffels" thing that we tend to get the wilder hands, even when hand-dealt - the plural of anecdote is not data, but I've had two "ruff-sluff on the opening lead" hands in the last two weeks, and both were hand-dealt (I can't remember the one before them, of course). I've stopped griping about "those damned computer hands" (when we have a wild hand-dealt night) because the point has been made (I *used* to get "but they're not computer dealt...Oh.")

[pran]

mycroft, on Feb 23 2010, 06:09 PM, said:

As a cryptographer, I agree with <strike>Wayne</strike> Helene.  Perfectly random is defined as p(deal X) = p(deal Y) for all X, Y; if some deals have a higher chance of being produced (the "flatter" ones), it's by definition less random. 

In Bridge, it's actually an issue:  if one knows that hands are skewed to the flatter end (more than, by sheer probability, they will be), it is sensible to build bidding systems around that fact, and to skew the card combination odds to reflect it.  One will have fewer unbiddable or "least lie" hands that way; one will make more contracts that way.  One will hate "those damned computer hands", though, because system, and play judgement, is now inferior to all the "true" systems that are inferior at the club.  Please note, I strongly believe that 20 years ago, this actually was the case (without any intent; the "invisible hand" of the market, so to speak), at least outside the full-time tournament play set.

Interestingly enough, enough people in my area know about the "moar shuffels" thing that we tend to get the wilder hands, even when hand-dealt - the plural of anecdote is not data, but I've had two "ruff-sluff on the opening lead" hands in the last two weeks, and both were hand-dealt (I can't remember the one before them, of course).  I've stopped griping about "those damned computer hands" (when we have a wild hand-dealt night) because the point has been made (I *used* to get "but they're not computer dealt...Oh.")

This is not just theory.

Culbertson called attention to something he named "factor X" reflecting the fact that card shuffling was seldom perfect and as a consequence the theoreticdal statistics in bridge tended to be erratic.

The Italian Blue Team was said to "shuffle the spots off the cards" when they were being behind in a match at half-time.

The reason? They knew that better shuffling produced more distributional hands for which they werer at an advantage with their strong club systems.

Back to OP:

I understand some of the arguments on this thread that Law 6D2 permits replay of boards previously played, but not boards that have been constructed in any (other) way?

What a funny logic if (provided proper announcement and purpose for the event) it shall be legal to include deals exactly as they were previously played, but not such deals if they have been modified in order to better suit the purpose of the event. (Such purpose will often be training of novices in bridge)

[bluejak]

The point of this forum is to help people with the Laws, not to decide what they should be. If you think the WBFLC have got it wrong, kindly tell them - or at the very least take it to the 'Changing Laws & Regulations' forum.

When the Law book says "replay of past deals" it does not mean "constructed deals".

[Cascade]

What if the constructed deal has been previously played?

[blackshoe]

This may be of help (I just found the link, I haven't read it).

[pran]

bluejak, on Feb 24 2010, 02:00 AM, said:

The point of this forum is to help people with the Laws, not to decide what they should be.  If you think the WBFLC have got it wrong, kindly tell them - or at the very least take it to the 'Changing Laws & Regulations' forum.

When the Law book says "replay of past deals" it does not mean "constructed deals".

No, I don't think WBFLC has got it wrong, but I think you put too much importance in the precise words used in Law 6.

Before 2007 Law 6 literally didn't allow duplicate bridge at all because duplicate requires replay at some tables of boards that had already been played at other tables. (Unless of course copies of the same deals were played simultaneously and syncronized at all tables).

Why didn't we bother? We used our common sense and slightly bent Law 6.

I agree that WBFLC could have worded Law 6 better in some respects, but why bother when we certainly know what they would most probably answer if asked?

Training of new players and encouraging them to play bridge is too important to splitting hairs about replay of unmodified previously played board versus using constructed boards that are particularly well suited for training purposes.

There are several laws in the book that could have been worded better; we do not bother with them. If in doubt we obtain clarification, if not in doubt we just go ahead and play bridge.

[mjj29]

pran, on Feb 24 2010, 04:27 AM, said:

Training of new players and encouraging them to play bridge is too important to splitting hairs about replay of unmodified previously played board versus using constructed boards that are particularly well suited for training purposes.

I don't think anyone is suggesting that you _shouldn't_ run games with constructed deals for beginners, in the same way that you are allowed to run a game with rigged deals to be outlandish, games where you introduce a silly new rule on every board, or single-winner total-points non-arrow-switched mitchells (to pick examples which happen at clubs I play in) if that's what you want to do. They can even count for any internal leader board which you run, however, since they are not technically 'bridge' they probably shouldn't qualify for master points or anything more formal (you wouldn't want it to be a qualifier for the county championship or something).

[pran]

mjj29, on Feb 24 2010, 12:40 PM, said:

pran, on Feb 24 2010, 04:27 AM, said:

Training of new players and encouraging them to play bridge is too important to splitting hairs about replay of unmodified previously played board versus using constructed boards that are particularly well suited for training purposes.

I don't think anyone is suggesting that you _shouldn't_ run games with constructed deals for beginners, in the same way that you are allowed to run a game with rigged deals to be outlandish, games where you introduce a silly new rule on every board, or single-winner total-points non-arrow-switched mitchells (to pick examples which happen at clubs I play in) if that's what you want to do. They can even count for any internal leader board which you run, however, since they are not technically 'bridge' they probably shouldn't qualify for master points or anything more formal (you wouldn't want it to be a qualifier for the county championship or something).

"Not legal" is a very strong clause.

I consider the clause purpose of the tournament in Law 6D2 far more important than the apparent literal limitation from the subsequent clause replay of past deals.

Why should an event specially arranged for training of beginners in bridge be illegal unless it used a selection of already played deals rather than deals prepared for the purpose?

[bluejak]

Because the Law says so unambiguously.

[blackshoe]

I had a director here say to me once "I can make any ruling I want!" I said "Of course you can, but that you make it won't necessarily mean it's legal". People run games all the time where something happens not strictly IAW the laws of bridge. If we're talking about "teaching" hands, and it's a sanctioned tournament (in the ACBL, a Sectional, Regional, or NABC) this should not happen. If it's a club championship it should not happen. If it's a regular club game where part of the purpose is learning about some aspect of the game, then I see no reason not to do it, even if it's technically "not bridge" according to the laws.

The point is, no one in his right mind is going to put "teaching" hands in a tournament, or a club championship. I would caution club managers to check with their NBO if they're going to put such hands in a regular club game that awards masterpoints. But if the purpose is teaching, just do it and don't worry about Law 6.

Let's move on. This horse is dead.

[FrancesHinden]

bluejak, on Feb 21 2010, 09:55 PM, said:

"The replay of past deals" is nothing like "Hands constructed for any puropse".  So it is not legal.

Maybe you should tell the EBU who have run such a competition at a national congress. (In fact I complained during the course of the event to little effect.)

Oh yes, and the EBU also award masterpoints (green points no less) for simultaneous pairs events that breach this law as you interpret it.

[jeremy69]

Quote

Oh yes, and the EBU also award masterpoints (green points no less) for simultaneous pairs events that breach this law as you interpret it.

Which simultaneous is this? I know there have bene ones where the hands have come from past deals, usually Reunion vs Netherland Antilles in a Bermuda Bowl qualifying where 6D makes on a combined 5 count. When they have occasionally trusted me with a commentary I have been given 3 computer sets of hands and allowed to pick the set but not allowed to mix and match.

There is an event at Brighton where past deals are played i.e. "Play with an Expert" Are there others that might breach this law? If so then the L&E should let the Tournament Committee know before they are taken off to prison!

[bluejak]

Yes, I am curious. Past deals is permitted under Law 6D2, so it cannot be those Sims.

[StevenG]

Where do the hands come from? from the ECats website may be of interest.

[pran]

StevenG, on Feb 25 2010, 01:54 PM, said:

Where do the hands come from? from the ECats website may be of interest.

Indeed it is. According to this the deals have never been played before so it is not a replay. However the deals have been manipulated in that some of them have been filtered out (not to be played) invalidating the dealing process.

[Vampyr]

pran, on Feb 25 2010, 07:02 PM, said:

StevenG, on Feb 25 2010, 01:54 PM, said:

Where do the hands come from? from the ECats website may be of interest.

Indeed it is. According to this the deals have never been played before so it is not a replay. However the deals have been manipulated in that some of them have been filtered out (not to be played) invalidating the dealing process.

And there is the problem that came up in another thread -- each player is given approximately the same number of HCP (or the same number of good hands) so that predictions may be made at the end of a session. This is just awful.

[shyams]

StevenG, on Feb 25 2010, 12:54 PM, said:

Where do the hands come from? from the ECats website may be of interest.

I remembered this; and had hunted for the information on the ECats website earlier once. I'm quite curious to know whether this is really legal.

Also, though the stated aim is to have nearly the same # of HCPs etc, I think it is meant to work only across the entire set of 32 or 36 boards. Most clubs would only have the first 24 or 26 boards in play -- rendering the HCP balancing exercise a bit futile.

[FrancesHinden]

StevenG, on Feb 25 2010, 12:54 PM, said:

Where do the hands come from? from the ECats website may be of interest.

Yes, that is what I was referring to on the SIMS. I don't think it's legal, and I think it's much worse than constructing deals to help teach people and telling them what you have done.

In practice it doesn't really make any difference to the players, because you usually play a subset of the boards and anyway there are a couple of rounds of arrowswitching which will ruin any of this careful preparation anyway.

The "play with the experts" at Brighton one year used the hands from the earlier BBC Grand Slam TV series, which were all carefully constructed "textbook play" deals. It took us a couple of rounds to work out what was happening, but then as my partner put it "I've never seen anyone play to make a slam on a trump endplay so quickly"