Internal blockage

Larry Hammick
larry@hammick.com
2003.08.20

	A7652
	KQ98
If this suit is 3-1 it will be blocked _after_ it is established. All
the non-winners in the short hand are higher than all those in the
long hand. This problem, called internal blockage, is easy to overlook
in planning the play, partly because it is uncommon, and partly
because one tends not to compare pips the way one compares honours.

We will illustrate the simpler solutions to internal blockage:
	A side entry in the long hand
	A discard from the short hand
	A duck within the suit
A specialized squeeze (a no-loser squeeze or a 1-loser triple squeeze)
or a throwin is sometimes an answer; see the articles "Squeeze
endings" and "Introduction to elimination play" at www.hammick.com.

If a side entry is available, declarer just plays out the short hand
before using it.
	A7652
	A

	KQ98
	xx
Declarer takes SAKQ and, if it is established, the S9. Now HA is an
entry for the long spade.

Here declarer makes an unblocking discard on a winner.
	Axx
	K76532
	--
	--

	--
	A98
	xxx
	xxx
If seven tricks are needed declarer plays off HAK (ending in dummy),
hoping for a 2-2 break. If they cooperate, he unblocks H9 on SA and
runs the hearts.

To illustrate the duck, and the discard on an enemy trick:
	--
	K76532
	x
	--

	x
	A98
	--
	AQx
Spades are trumps, they have been pulled, and declarer needs six more
tricks. If North or South is on lead, declarer ducks a heart, and can
run the remaining hearts unless they are 4-0. But suppose West is in
and leads a diamond. Declarer's only chance is to discard a heart on
this trick, win the next, and try to split the hearts 2-2.

Here is a more exotic problem in internal blockage. The hand was
reported in the Sharif-Hirsch newspaper column.
	KJT9
	J62
	K75432
	--
--		7532
T9874		AQ53
J6		QT
K98654		QJT
	AQ864
	K
	A98
	A732
Against an optimistic 6S contract, West leads HT to East's ace.
East switches to CQ. Declarer will need diamonds 2-2, but what
to do about the internal block if trumps are 4-0? The solution
is a dummy reversal, enabling declarer to unblock a diamond on
dummy's trumps! Declarer takes trick two with CA, discarding a
_diamond_ from dummy. Then he plays a trump to the 9 and ruffs
a heart. He should play off DAK next, cutting his losses if the
suit is not 2-2. Next comes a heart ruff with the ace, and now
declarer's trumps are shorter than dummy's. Declarer just
overtakes SQ with SK and runs dummy's trumps, unblocking a
diamond, and dummy takes the last three tricks in diamonds.