Double Dummy Corner

 

4th exchange for Exchange & Win No. 17

♠ A2

 AJ10

 Q1073

♣ J862

♠ J10873

 KQ2

 98

♣ 954




♠ K

 9876543

 KJ4

♣ Q3

♠ Q9654

 none

 A652

♣ AK107

South is declarer in five no-trumps.  What is the winning exchange?

What sequence of counter-exchanges follows?

The fourth winning exchange is to swap North's ♣7 for South's ♣8.  The cost is 8-7=1. We do not multiply by two this time, because the exchanged cards belong to the same side.  Now a seesaw squeeze is available again, this time using clubs, not diamonds, as the seesaw suit. The fourth round of diamonds, which must be won by South, forces West to part with a club.  With ♣107 opposite North's ♣J8, South leads the ♣7 and North plays high or low according to West's discard.

East-West is now the losing side and we must find a counter-exchange that makes them the winning side again.  The counter-exchange must be cheaper than the fourth exchange.  It cannot cost less than 1, obviously, so it must involve lower cards or a lower suit than clubs, under Rules 6 and 7.  It shouldn't take you long to verify that no exchange of adjacent cards lower than 8 and 7 in the same suit between East and West allows the contract to be defeated, so the fourth exchange is the last and we have completed the solution.

E&W #17 Problem #129    
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        Hugh Darwen, 2001

Date last modified: 11 March, 2017