West leads the ♦Q and East discards the ♥7. Three more rounds of diamonds follow. Can you find the 100% play? Be specific.
When West plays four rounds of diamonds, you must unblock three of your top four diamonds and if West continues with the ♦7 (best), allow West to hold the trick by “underplaying” with the ♦3! What can West do? If West leads a heart, you have nine tricks: three hearts plus three in each black suit. If West leads a black card, the 10–9 in dummy ensure a dummy entry to the hearts.
If you don’t unblock the diamonds, you could lose two more tricks.
From Bridge D’Italia.
West leads the ♠K to dummy’s ace and East’s 3. When you play the ♥A K, West discards a spade on the second trump. Take it from here.
The solution hinges on getting a fuller count of the layout by cashing three rounds of diamonds and noting how many West follows to.
As West has eight known cards, he can have at most five diamonds, so it’s safe to cash the ♦A K Q. If West has a singleton diamond and a 7–1–1–4 shape, however, you can’t afford to play a spade (with the idea of ruffing a third spade high in dummy) because East will discard his club and get a club ruff in return. So after discarding a low spade on the third diamond, draw trumps, forcing West to discard from ♠Q 10 and ♣Q 9 8 4. If he throws a spade, cash the last trump and exit a spade; you’ll take the last four club tricks from the forced club return. If West discards a club, cash the ♣A and take four clubs via a club finesse through West.
If West has exactly two diamonds, he must have three clubs, so draw trumps and play West for the ♣Q.
If West follows to three diamonds, he has at most two clubs. So finesse East for ♣Q before drawing trumps. The wrinkle comes after you finesse East for the ♣Q and East turns up
with four clubs. Say this was the starting layout:
After winning the ♠A, cashing the ♥A K and the three top diamonds (West following to all three), these cards remain after you have cashed
the ♣K and led a low club to the 10:
Cash the ♥J and exit a spade. If West wins, he has to concede a ruff-and-discard. End of story.
If East ruffs partner’s winning spade with his last trump, he must lead away from his ♣Q or lead his remaining diamond, both equally disastrous.
Thanks to Tim Bourke, Australia, for this lovely construction.