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From: laura@utcsstat.UUCP (Laura Creighton)
Newsgroups: net.math,net.misc,net.rec.bridge
Subject: Re: simple (?) statistics problem solved
Message-ID: <908@utcsstat.UUCP>
Date: Fri, 19-Aug-83 10:08:43 EDT
Article-I.D.: utcsstat.908
Posted: Fri Aug 19 10:08:43 1983
Date-Received: Fri, 19-Aug-83 10:40:24 EDT
References: <1814@rabbit.UUCP>, <903@utcsstat.UUCP>
Organization: U. of Toronto, Canada
Lines: 65

I am getting answers to why I was wrong, but I am still confused. I
think I can express my confusion better now, though. (I still don't
know what is going on, but I misunderstand *much* better today).

If you had phrased the question "What is the chance that you picked
the drawer with the 2 gold coins", I would have come up with the official
answer to the problem. your start condition is a room with three cabinets
in it.

But you *didn't*. The start condition is with one drawer open. You get
to do a rescan of the sample set, and, noticing that one cabinet has
been eliminated from consideration, you *eliminate it*. You are only
left with 2 cabinets, and they are (obviously) equal in proportion
to each other with regard to the property (having another gold coin)
that you are testing.

The official answer says that I do not get to do that rescan. I do
not understand why not. 

I also think the same way when I am playing bridge. You count up your
sure tricks, and then consider how to make the best out of the rest
of the deal. (you had better make sure you have leaders to both the
board and your hand as well). If you do not know the distribution of
cards in your oponents hands from the bidding, you may have the situation
that you mentioned. In some cases, you have no choice. Either the
finesse fails, and your contract goes down, or it doesn't and you are
safe. Lay on MacDuff... (actually, you may have to think about when to time
your finesse but if it is the only way that your contract is going to make
it, then it is the only way that your contract is going to make it.)   

Frequently, though, there is another way out. You hold onto your high card.
You then apply a squeeze. For people not aquainted with the sqeeeze, the
idea is for you to run all your cards out, usually fairly rapidly, to
increase the intimidation factor, and sqeeze your oponent, who does not know
what card you have, into dropping a card that would have won him a trick.

For instance, suppose you are south, and are holding the Ace of hearts,
and the 10 of hearts, and the Ace of spades. Your west opponent has
the King and Queen of hearts, and the Ace of clubs. Your East opponent
has the King of clubs and some losers. If you run the squeze on West,
he is going to have to decide between keeping the Queen of Hearts and
keeping the Ace of Clubs. Remember, he has the possibility that you have
the King of Clubs and the Ace of Hearts, and that his partner has the 
10 of Hearts to consider. 

I would do this rather than trying to finesse east, unless from the bidding 
it was obvious that the missing King of Hearts was in East's hand.

You understand the squeeze? The reason that I use it is that I get to
see a lot of the cards fall and can do a lot of rescanning. It also
works more often for me than trying a finesse. You can see your odds get
better and better....

In fact, it is most important to keep track of the distribution of cards
as they fall. You must assume that unless your opponent West is a fool
he is doing the same. If he finds out that you are void in clubs early
on, the show is over, for he will know where the 10 lies.

Okay. I rescan constantly when I play bridge. you say that I cannot
rescan when I open cabinets. Why?  Why is your puzzle applicable to bridge?

Always interested in finding new ways to win more often at bridge,

Laura Creighton
utzoo!utcsstat!laura