Competition Problem 109a
South to make four no-trumps. West leads the ♦5.
Successful solvers: Jean-Marc Bihl, Steve Bloom, Bülent İyidoğan, Radu Mihai, Sebastian Nowacki, Wim van der Zijden Tables
North wins with the ♦K and leads a club, South playing the ♣7!
A. If West wins and leads another diamond (best), South wins with the ♦A and plays spades from the top. North wins as soon as West covers, then South takes the club finesse and cashes any remaining spade winners. This is the ending, with East to discard at trick 7:
1. If East discards a heart, South exits immediately on a diamond. If East cashes the last diamond, the ♣A will squeeze West in the major suits. If East instead leads a club without cashing the diamond, then West is thrown in on a spade as North keeps three hearts and North-South take the last three tricks, South wining the heart return with the ♥A over East’s ♥Q and leading the ♥10 to pin the ♥9.
2. If East discards a club, South cashes the ♣A and throws West in with a spade. If West cashes the ♣J now, North comes down to three hearts and East is squeezed before South, a heart discard leading to the same ending as in 1. If instead West leads a heart without cashing the club, then East is thrown in on a diamond to lead away from the ♥9.
B. If East wins with the ♣8, declarer can succeed as in line A except when East returns the ♥9. This is covered in turn by the♥10, ♥J, and ♥K, then South takes the club finesse and leads the ♠2, North playing low! Three rounds of spades and the minor suit aces, North discarding a diamond on the ♣A, force East down to a winning diamond and ♥Q7, only to be thrown in on a diamond to lead a heart into the split tenace.
See the solution to Competition Problem #4 for the recommended tabular format if you prefer not to write in English prose.
Hugh Darwen, 2014