Talk:Principle of restricted choice (bridge)

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I'm not sure that my description of the PRT is clear. Should I/someone else remove the combinaitons that don't matter?

Totally unclear.

Any suggestions to improve it then? Cambion 17:41, 5 April 2006 (UTC)

[edit] Jargon

This article is full of jargon that can't be understood just by referring the bridge glossary page. I have no idea what these terms mean; could someone in-the-know please clarify? Thanks for any help. --P3d0 19:05, 23 April 2006 (UTC)

• "an opponent unprovoked": "provoked" is not in the glossary.
  • Not jargon here; it just means the card was played without an apparent reason to (eg to force a higher one). This means that is was probably singleton or they hold another of equal rank.
• "AJT9x opposite xxxx": I don't know what this notation means, nor what "opposite" means.
  • One hand (eg dummy) has AJT9x and the hand oppsite (eg declarer) has xxxx. x means a small card who's value is not significant.
• "led to the Jack": the glossary entry on "lead" doesn't explain this phrase.
  • A card is lead from the hand opposite to the jack (in this case from declarer's hand towards dummy.
• "crush the Queen": no glossary entry for "crush".
  • Not jargon really; it just means that the queen is beaten by teh higher card.
• "lead towards the AT9x": what does it mean to "lead toward" something?
  • See above.

I've put in the answers above - can someone make the article clearer please? I'm used to all the jargon so maybe someone other than me should to it. Any thoughts on whether the above things should go in the glossary? Cambion 14:40, 25 April 2006 (UTC)

Ok, I have tried to do so. Not being a bridge player, I might have made the example incorrect, but I hope you see the sort of thing I'm looking for. --P3d0 17:51, 26 April 2006 (UTC)

No problem :-). As a non-bridge player, you might have chosen a wrong article to start with; many bridge players don't get the principle -- is it inavoidably difficult to explain to non-math geeks? Duja 23:30, 28 April 2006 (UTC)

The example is much clearer now. Thanks! --P3d0 16:28, 28 April 2006 (UTC)

[edit] List format

Is it just me or did it look better with a simpler list eg:

• abcde
• abcdef
• abc

rather than the spaced out thing that doesn't seem to line up horizontally?Cambion 12:47, 17 July 2006 (UTC)

The problem with simpler list is that doesn't line up vertically. I also see the slight misalignment horizontally. I'll give it a try with a straightforward table. Duja 15:25, 17 July 2006 (UTC)

[edit] Quack

I think we should try to avoid the term "quack" unless it's really awkward. We're not computers, so having a "declaration" of what the word means up in the article intro isn't sufficient to avoid confusion, as Ralian recently demonstrated. At least, the word "quack" itself should be a hyperlink to the appropriate definition; but my vote would be to reword the article without using "quack" at all. --P3d0 17:06, 31 July 2006 (UTC)

My apologies! I've been playing bridge for quite a while now and have amazingly never run into this -- rather hilarious -- terminology. I instantly grasped what it meant but thought it might have been either a typo or joke =P ralian 00:13, 2 August 2006 (UTC)

Ralian -- NP. My use of "who have played bridge" was not meant to refer to you. And Jeff Rubens, who appears to have invented the term quack, surely was being a little facetious at first, but the term turned out to be a valuable one. Xlmvp 00:29, 2 August 2006 (UTC)

I quite like 'quack' - It reminds me of quantum mechanics which this is related to. Heh - I always like the idea of a quantum queen which collapses into the wrong hand when you take a 2-way finesse.

I think that prior post is from Cambion. I agree: quack is conceptually useful and should be retained. However, I think that P3d0 is correct, that there should be a link to the contract bridge glossary and I'll make one. (As to quantum quacks -- I find the notion of one quack existing simultaneously in two different hands far too disconcerting. Am I supposed to go in search of Schrödinger's quack? Is that what happened to Billy Heisenberg?)

However, I completely disagree with P3d0's rewrite of the material at the beginning of the article, and I'm going to revert it. The changes that were made include errors of fact and diction, and are stylistically inferior (although the latter is a subjective judgment).

I disagree with the complaint about jargon. Were the article concerned with an elementary concept, there would be reason to go easy on the technical terminology: a neophyte could not be expected to understand, and its presence would be at least annoying. The Principle is not an elementary concept, however, but an advanced one, and the article cannot cater to all degrees of experience and knowledge. I can't be expected to write an article about Cox proportional hazards regression without mentioning relative risk, any more than a student in Statistics 101 could be expected to know what I was talking about.

Furthermore, the example is neither redundant nor "extraneous." The introduction needs a relatively quick -- in this case, three-sentence -- overview of the principle, whereas the body of the article requires a fuller explanation. (And BTW, the article could go much further than it does, covering cases that give even better odds, such as AKQ10 opposite 432). So, because people who have played bridge spent a fair amount of time crafting the introduction, I'll put it back the way it was. Xlmvp 21:54, 31 July 2006 (UTC)

The comment was mine - I messed up signing it somehow. One thing that should probably be noted is that PoRC has links with maths (Baysian stats) and the Monty Hall problem (which was a FA a while ago) bringing in people who are not bridge players. It might be a good idea to make this article more approachable for that reason. Cambion 12:46, 2 August 2006 (UTC)

Fundamentally, I think what it comes down to is that we're not writing a bridge text here, so it doesn't matter how necessary the jargon is: if it won't be understood, it doesn't belong; and if that means this article isn't appropriate for Wikipedia, then, well, I'm not sure what we would do. Fortunately I don't think that's the case here. This is primarily a mathematical concept -- the fact that it arises in bridge is almost secondary -- and I think we can achieve the required level of clarity if we keep polishing the article. I'll continue to offer my services as the bridge ignoramous and spot the parts that are incomprehensible if you folks will agree to keep reverting me when I botch things. I think we're on the right track; let's just keep on progressing toward an article that we're all satisfied with.

Xlmvp - thanks for reverting me. I think I got a little too bold. I'm intrigued by your AKQT and 432 case; can you add that to the article? --P3d0 19:40, 2 August 2006 (UTC)

P3d0 -- I apologize for not having responded before now. I had this page on my watch list but I don't think I saw your query when you posted it. I just now came across it in the process of making some corrections at the end of the article.

As to AKQT opposite 432, that was careless, and again I apologize: the odds in favor of dropping the J on the third round are 51-49. The dramatic setup, one that the Principle really does bear on, is AKQ8 opposite 432. Suppose you play off the AK from North, and East follows with the 9 and then the 10. You come to hand and lead your last small card, and West follows low. Now the principle offers odds of not just 2:1 but close to 3:1. If East started out with JT9, he had six ways to play two of his minor honors, and he chose one of them from his extended quack. (Six ways: JT, TJ, J9, 9J, T9, 9T.) A priori, a 3-3 split occurs 35.5%, and there are 20 ways for that to occur, so specifically JT9 is 35.5% / 20, or 1.78%. Dividing that 1.78% by the one-sixth chance of selecting the 9, then the T, from JT9 is 1.78% / 6, or 0.3%.

In contrast, a 4-2 split is 48.45% a priori and there are 30 combinations, so 48.45 / 30 = 1.62% for the T9 doubleton. There were two ways to play those two cards, so 1.62% / 2 = 0.81%.

0.81% vs. 0.3% is slightly less than 3:1 (actually, 2.7:1).

Two questions: (1) Are you sure you want that in the main article? (2) Frank Loesser could never have woven "... It's a probable 2.7 to 1" into Guys and Dolls, so I just think of it as 3:1. Xlmvp 20:56, 25 September 2006 (UTC)