The opening lead is a small club. You duck, losing to the King, and the club return is ruffed. East now plays the spade Ace and switches to a diamond
This isn’t exactly a tough hand but I thought it interesting because it shows how much information is often available.
Presented as a problem, I expect most intermediates or better would work this out. The secret to becoming a good player is to pay attention on every hand, such that (over time) this sort of thinking becomes second nature.
Opener would not cash the spade Ace and play a diamond if he had Axx in spades to begin with: if he was going passive, he’d exit his last spade and if he was hoping for another ruff or to retain control he’d not cash the spade.
More importantly, he’d never lead a diamond if he had a heart sequence, nor would he cash the spade Ace. He’d drive out the heart Ace while he still had control in spades.
He’s marked with the diamond King for his opening bid, and he can’t hold KQxxx(x) in hearts because he’d switch to the heart King rather than cash his spade Ace.
So we can infer that he held either Ax KJxxxx Kxxx x or Ax KJxxx Kxxxx x
So where does that leave us? We’ve lost two tricks already.
We have 2 club winners, 2 diamond winners and one heart. So we need 5 trump tricks, but west has 8x in spades sitting over dummy’s Q7. We need to ruff one heart with the 7 and another with the Queen….those two ruffs will, combined with our KJ10, give us 5 trump tricks.
This means that we need west to hold Qx in hearts.
Win the diamond in hand. We can afford to cash one spade just in case east fooled us and did start with Axx. He shows out, as expected.
Cash the club Ace and then this being the critical play, unblock the heart Ace. Cash diamond Ace, ruff a diamond, and take a heart pitch on the good club Queen. Now ruff a heart with the 7 and score 3 more tricks by way of a high cross-ruff.
Note that if you don’t unblock the heart Ace, but instead ruff a diamond to hand…then pitch a heart on the club and cross to the now stiff heart Ace, when you ruff dummy’s last diamond, west pitches his Herat Queen and down you go.
I thought this was a good hand. If you’ve ever wondered how experts seem to play double-dummy, it’s often based on this kind of inferential reading. This hand was one of the easier ones…..we have basically a complete read of the opponents’ hands at trick 4.
Yes, they should have beaten us by switching to a heart rather than cashing the spade Ace, but defenders often make errors and it’s declarer’s job to make them pay when they do.