Competition Problem 180
There are two parts to this problem, A and B.
How do East-West defeat South's contract of six diamonds?
Successful solvers: Ed Lawhon, Steve McVea, Sebastian Nowacki, Rajeswar Tewari, Xiao Tiannan. Some solvers missed the correct play in Part B.
A passive lead is no good. For example, suppose west leads the ♦7. After four rounds of diamonds, North playing low, we have
The next diamond brings pressure to bear on West.
1. A spade discard allows South to take the club finesse and at some point lead a low spade from hand. Whether West plays the ♠6 or the ♠Q, declarer gets two spade tricks.
2. A heart discard allows North to lead a spade to the ♠10 and ♠Q. South wins the major suit return and then the ♦9, North discard a spade or club, triple-squeezes East: a major suit discard is immediately fatal, whereas a club discard gives rise to a second squeeze when the club winners are taken.
3. A club discard brings East under pressure:
(a) On a spade discard North can lead any spade to set up a second trick in the suit.
(b) On a heart discard declarer can win two club tricks, ending in either hand. If North is on lead the ♠J is covered by the ♠K and South can either duck or win with the ♠A, West becoming squeezed by the last diamond (possibly ruffing Eastís club winner) in either case. If South is on lead a low spade to the ♠J and ♠K has the same effect.
(c) On a club discard, two club tricks bring both defenders down to three cards in each major suit. If necessary, South comes to hand on the ♥K and then the last diamond, North discarding a spade, forces at lest one defender to discard a spade. If it is West (or both), South then leads a low spade to guarantee two tricks in the suit; if it is East, North is entered on the ♥A to lead the ♠J.
To defeat the contract, West must lead the ♥Q. Declarerís best plan is to win and follow the above line. West must not discard a club! Contrariwise, East must discard nothing but clubs. In fact, both defenders must keep three spades and two hearts in this ending.
On the next diamond West must throw a heart, East another club.
4. If North now leads the ♣10, East plays low to deny North a re-entry in that suit. There is no longer any play for the contract.
5. If North tries the ♠J, East plays low! West returns a heart and North cannot now take both black suit finesses.
The minor changes in the second layout cause this defence to fail, as we shall now see.
cards have been swapped: the ♣J and ♣10 and the ♥8
Declarer and defenders play as in the first layout, leading to this position with North on lead:
This time, when North leads the ♠J East must cover. South wins with the ♠A and plays the last diamond. West does best to discard a heart, East a club, but a heart to the ♥A finally wrings a club from West and now the ♣A and ♣Q squeeze East. Southís ♠7 threatens to win the last trick, via a spade to Westís ♠Q, if East discards a spade.
Note that if West discards a club on the fifth diamond, keeping the ♥6 in place of the ♣2 in the above ending, then declarer plays as in variation 3(c) given for layout A.
Hugh Darwen, 2020