Competition Problem 171a
South to make three hearts. West leads the ♦K.
Successful solvers: Steve Bloom, Steve McVea, Sebastian Nowacki, A.V. Ramana Rao, Zoran Sibinović, Rajeswar Tewari, Dick Yuen, Wim van der Zijden. Suggested DRs ranged from 3 to 7, mostly on the higher side of that range.
South wins with the ♦A and leads a low spade, North playing the ♠9 under Westís ♠10! West must now lead a red suit card to cause any difficulty.
A. If West returns a heart, declarer draws trumps, North winning the first if East ducks, allowing South to finesse on the second round and then drop Eastís ♥K. North discards clubs. Now put on play with a diamond, West can cash the other diamond winner but then has to open a black suit.
1. If West leads a spade, North plays the ♠Q, forcing the ♠K from East. South wins with the ♠A and plays the ♠8. If this wins, then the ♠6 is good; otherwise West wins with the ♠J and has to lead away from the ♣K.
2. If West leads the ♣K, North wins and can lead either spade to guarantee losing a trick to West in that suit (e.g., ♠Q to ♠K and ♠A, then spade to Westís ♠J). South makes two spade tricks and the ♣Q.
3. If West leads a lower club, declarer wins with the ♣Q, plays another to Northís ♣A and throws West back in with a third club, discarding the ♠6 from hand and making the last two tricks on Westís spade return.
B. If West returns a diamond, North ruffs, plays the ♠3 to Southís ♠A, ruffs another diamond, cashes the ♣A (which could have been done at trick four) and exits on the ♠Q to Eastís ♠K. South ruffs the diamond return (best) and exits on the ♣Q to Westís ♣K. South is left with ♥AQJ and the ♠8 and cannot be prevented from making all three heart tricks.
Trap: If North plays the ♠3 at trick two, play follows A.1 but that line fails when West leads the ♠J and the suit is blocked by Northís ♠9.
See the solution to Competition Problem #4 for the recommended tabular format if you prefer not to write in English prose.
Hugh Darwen, 2019