Competition Problem 147a
(a) South to make five spades.
West leads a diamond.
Successful solvers: Ian Budden, Johnson, Leigh Matheson, Radu Mihai, Sebastian Nowacki, Zoran Sibinović, Rajeswar Tewari, Dick Yuen, Wim van der Zijden. The DR is affected by several solvers' observation that the wording of part (b) gives a big hint as to the necessity to drop the ♦Q at trick one, but also by the fact that not everybody solved part (b) correctly. Tables
(a) North takes the opening diamond and South drops the ♦Q. After three rounds of spades, a heart to South and two more spades this is the position:
South leads the ♠7. West and North discard clubs and, East is squeezed down to the four hearts and two minor suit cards. South cashes the ♥K. South leads a club if East still has the ♣K, otherwise a diamond. In either case East cannot avoid being on lead at trick twelve with two heart losers.
(b) The plays proceeds as in (a) but East takes care to preserve the ♦6. The 4-card ending is now like this, with South on lead:
Note the careful discarding by East and West. A club exit allows East to discard a heart and take two diamond tricks, so South tries the ♦8, but this is allowed to hold! East then discards the ♦K on the ♣A and West’s diamonds take the last two tricks.
This defence explains why South drops the ♦Q at trick one in (a)—if North can beat South’s diamond in the ending, then the ♥A and ♥J yield an overtrick if East futilely ducks.
See the solution to Competition Problem #4 for the recommended tabular format if you prefer not to write in English prose.
Hugh Darwen, 2017