Crystal Clear

[OliverC]

Defence is always difficult, but sometimes the position is crystal clear, and it shouldn't be difficult to chat your way through the shoals:

You are North, EW Game, Dealer East

Bidding
East     South     West     North
No        No          1        1
2       No          4        All Pass

Partner, (South) leads the 8 and you can see

                    West (Dummy)
                    KQ6
                    A82
                    Q10962
                    A6

North (You)
A109543
10
K873
K3

Dummy plays low. You rise with the Ace and play another Spade to Declarer's Jack, Partner's 7 and Dummy's Queen. Declarer now continues with the King os Spades, on which they throw a small Diamond and Partner ruffs. South now Cashes the Diamond Ace, drawing the Jack from Declarer, and then leads the Queen. Declarer rises with the Ace in Dummy and leads the Queen. What do you do?

                    West (Dummy)
                    -
                    A82
                    Q1096
                    6

North (You)
954
10
K87
K

Here the position is crystal clear: Partner started with 2 Spades, Ax, probably 4-card (no 2 Opener from East) and therefore something like QJxxx in Clubs (probably QJ10 or QJ9). That means Declarer started with something like !SJx, KQxxx, Jx, xxxx. You must just allow the Queen to win, here. Declarer will discard a Club, and if yet another Diamond comes through you must duck again, in the knowledge that Partner can ruff this one. Declarer now probably has only one entry back to Dummy (A ).

If you were really on the ball, BTW, did you think to ditch the King under the Ace?

Covering the Queen of Diamonds sets up the Diamonds in Dummy before partner is ready to ruff or overruff and Declarer can draw trumps ending in Dummy and enjoy all those Diamonds.