Crisscross duck

Larry Hammick
larry@hammick.com
2000.07.09

Declarer can sometimes overcome blockage in one suit by deliberately
blocking another suit "in the opposite direction". We suggest the term
"crisscross" for such a position, after the crisscross squeeze:
      A
      Qx

      Qx
      A
If the same defender started with both kings, he is squeezed on trick
ten.

An illustration of the crisscross duck:
      xxxxx
      KQ
      AJx
      Axx

      AKx
      Axx
      xxxx
      JTx
West leads a heart against your 3NT. You have nine tricks if spades
are 3-2, but if you start with SAKx you will be cut off from HA. You
should duck a spade at trick two, or cash dummy's remaining heart and
duck the first or second round of spades. You can now untangle the two
blocked major suits. Observe that it is not good enough to cash the SA
at trick two and then duck one, for the defence might lead a third
spade, removing the last entry to HA.

      AJxx
      K
      xxxx
      xxxxx

      Txxx
      Axxx
      AK
      AKx
A diamond is led against 3NT, and you duck a club. Two suits are now
blocked but the other two contain an entry to each hand. If the return
puts you in dummy, you unblock dummy's suit (clubs) first, but if it
puts you in hand, you take HK to free your own winner in hearts.

      xxxx
      AT
      AJx
      QJxx

      Jxxxx
      KJxx
      Kxx
      AK
A diamond is led against 3NT. Nine tricks are certain provided that
you play low from dummy, win in hand, and finesse the HT. This
sequence prevents the defence from removing dummy's entry in diamonds
before dummy's suit (clubs) is unblocked.

A void is similar to a blocking winner for the purpose of the
crisscross duck:
      xxxxx
      A
      AJx
      Axxx

      AKx
      KQx
      xxxx
      JTx
West leads a heart against 3NT. Declarer ducks the first or second
spade.

A duck is sometimes made to conserve an entry at the cost of a
possible overtrick.
      AKQxxx
      xx
If North has no side entry but declarer needs only five tricks here,
he may duck the first round to protect against a 4-1 break. A similar
duck in crisscross form may likewise prevent two or more winners from
getting marooned.
      Ax
      AKxx
      xxx
      xxxx

      KQxxxx
      Q
      AKx
      AKx
Against 6NT West leads something other than a spade. Declarer wins in
hand, takes HQ, and then ducks a spade, ensuring twelve tricks unless
spades are 5-0.

At a trump contract also, an early duck in a side suit will sometimes
overcome an entry problem. Such a duck may take a crisscross form, to
preserve an entry to the trump length, for the purpose of pulling
trumps.
      KQx
      x
      KQxxx
      AKxx

      AJTx
      Axxx
      Ax
      xxx
Against 6S West leads a trump, taken in dummy. On any other lead you
would try to ruff two hearts, but now the best chance is score one
ruff plus one long diamond. You should duck a diamond right away.
Suppose you were to take HA and a heart ruff, SK, DA, and pull trumps.
Unless trumps were 3-3 it would be too late to concede a diamond,
since you would be out of trumps. Nor would it be good to start with
DA, which you will need later as an entry to pull trumps.