wildbill@ucbvax.ARPA (William J. Laubenheimer) (02/06/85)
Now that bridge activity has once again begun in the Bay area (no tournaments
of any kind closer than Palm Springs during January), I should be able to
pick up a few problems worthy of being passed along to the net every once
in a while. I was at the table for one such problem last weekend. The
nature of the problem seems to lend itself best to a format which I have
not seen used in this newsgroup, although it would seem to be quite
suited to the electronic medium: that of the "Bridge Movies" which
appear from time to time in \\The Bridge World//.
For those who are unfamiliar with the format, a Bridge Movie presents
a deal which presents a sequence of problems, as opposed to what is
usually a single problem in the typical single- or double-dummy format.
The points where these problems are reached are marked. To "watch"
the movie unfold, read the text until a question is encountered, answer
the question, and then check your answer against the provided answer;
this continues until the deal is complete.
In this movie, each question will be followed by a row of asterisks (*)
and a form-feed. Thus, anybody reading this message using "more" or
many of the popular news interfaces will see the display stop just
before the answer to a question would be revealed. So, without further
ado, I present:
USENET Bridge Movie #1
Matchpoints S- A K Q 9 8
Both Vul. H- K Q 5 2
(but it really doesn't D-
matter much) C- A Q 7 3
S- 5 4
H- A 6
D- A Q 8 7
C- K J 10 5 2
Contract: 7S by South (don't ask how you got tplay this from the wrong
side of the table -- you don't want to know...). Opponents are strong but
not expert.
Obviously, you must avoid a trump loser. If you can do this, you should
make the contract. What plays are open to you in the trump suit?
*************************************************************************
You can play three rounds of high trumps, hoping to drop the jack and ten.
You can finesse twice against West, succeeding any time he has J-10 no
more than 5 times. Or, if East drops an honor on the first or second
round of high trumps, you can play for a coup against West, which may
succeed when he has one honor fourth or fifth.
The opening lead is the diamond 3 (third/fifth). What do you play from
dummy?
*************************************************************************
A club. It might be safest to play the ace, but in practice, any one
will do. The opening lead has given you an extra chance should you
elect to try the trump coup. By throwing a club on this trick and
another club on the other high diamond you will have, you can succeed
any time West has at least two clubs, as opposed to the three clubs
you would have needed him to hold with another lead.
You play the three; East produces the king, and you win with the ace.
You lead a spade to the ace; West plays the deuce and East the jack.
Can you deduce anything about the lie of the trump suit?
*************************************************************************
Not for certain. If you were only comparing the holdings of singleton
jack and J-10 doubleton, the Rule of Restricted Choice would suggest
that the singleton was more likely. Unfortunately, any reasonably strong
East will play an honor from J-10-X as well. So, in order to apply
restricted choice, you must weigh singleton jack against J-10 doubleton
or third. The important thing is not the exact percentage, but the
relative odds on each combination.
Can you play another round of high trumps to find out what's going on?
*************************************************************************
No. Unfortunately, you lack the entries for a double trump coup. If you
play another high trump and East shows out, West can defeat you by
ruffing your winners so that you either have no entry back to your hand
after drawing his trumps, or no entry for the second coup so that he
makes a trump trick. So you must figure out what is happening now;
if you thing West has five trumps, you must finesse in trumps.
Which combination is favored?
*************************************************************************
Suppose you cross to your hand and lead your last trump. When West
follows low, there will be two low spots remaining. Thus, ignoring
the basically small changes in percentages due to the number of known
cards in each hand (which is partially offset because you know from
the opening lead that East has at least one more diamond than West),
and considering all original spade distributions equally probable,
there are three J-10 holdings to consider vs. only one singleton jack
holding. If East is awake, and (as he should) will always play the
jack or ten from J-10-X, the odds after applying restricted choice
are approximately 1.5 to 1, or 3 to 2 in favor of East holding the
ten. The less likely East is to remember that he must falsecard from
J-10-x, the more likely the jack is to be singleton. You also have to
accept the fact that if the jack is singleton, anybody in 7NT will
make easily by squeezing whichever of East or West holds four or
more hearts...but that's beyond your control now. But it's late,
East may not be awake (especially after partner may have picked off
his diamond king), and besides, you're in the movies...
You cross to your club ten and play your spade. West plays the three,
you take a deep breath, and play the eight. East discards the four
of diamonds. You're right where you want to be! Now you can begin
thinking about how to run the trump coup. Do you need to do anything
before crossing to your hand?
*************************************************************************
Although it's not really necessary, you might as well play another
high trump, throwing a diamond. This will leave you with the basic
coup position of Q-9 over 10-7. All you have to do is to make sure
you can cash enough winners whenever West chooses to ruff in. This
requires some thought. If West has 3 clubs, anything will work. You
can cross to your hand on the third round and play the heart ace.
If that lives, your diamond queen eliminates dummy's last low heart
and the clubs complete the coup.
What breaks down if clubs are 2-2?
*************************************************************************
In this case, you will have to throw another club on your diamond queen.
This will leave two small hearts in dummy. And you have to save the heart
ace to guard against an early ruff by West leaving you stranded in dummy.
West will throw hearts on your clubs, and you will be left with a high
heart in each hand, a low heart and a losing diamond in your hand, and
the two trumps in dummy. Unless West strated with four or more hearts,
he will be able to ruff your heart ace and defeat you. So you must
play a \\high heart from dummy//. After this, you can cross with the
club queen to your king, throw dummy's last club on the diamond queen,
and run three rounds of clubs at West. If West ruffs in, you can pull
his last trump and return to your heart ace and good clubs; if West
never ruffs, he is couped at trick 12. This line succeeds whenever
West has at least two clubs and one heart. The complete hand:
S- A K Q 9 8
H- K Q 5 2
D-
C- A Q 7 3
S- 10 7 6 3 2 S- J
H- J 9 4 H- 10 8 7 3
D- 10 5 3 D- K J 9 6 4 2
C- 6 4 C- 9 8
S- 5 4
H- A 6
D- A Q 8 7
C- K J 10 5 2
[Author's note: I was East on this hand. South did not seem to give
any consideration to the above line, simply playing out the high
trumps and conceding down 1 when I failed on the second round.]
Bill Laubenheimer
----------------------------------------UC-Berkeley Computer Science
...Killjoy went that-a-way---> ucbvax!wildbill