Source: http://cdn.acbl.org/nabc/2018/02/bulletins/db4.pdf
Dealer South. Both Vul
 10 5 4 9 2 A K Q K J 7 5 3 |
||
| 7 6K Q 5 49 7 410 9 6 2 |
9 8 2A 10 8 310 8 6 3 2A |
|
| A K Q J 3J 7 6J 5Q 8 4 |
| West | North | East | South |
| 1 |
|||
| Pass | 2 |
Pass | 2 |
| Pass | 4 |
End |
Opening lead: K
Bidding commentary: As South, treat a solid five-card major suit as a six-card suit and bid accordingly.
Defensive commentary: As East, avoid the common defensive error of signaling interest or disinterest in the suit partner has led (K) before looking at the rest of the hand.
Here you have the blank A and would like a club ruff. You can get it but you must overtake the K, cash the A, exit a heart to partner’s queen, and ruff the club return. Down one.
If you look only at hearts, you are apt to signal encouragement to show the ace. Once partner continues a heart, goodbye club ruff, goodbye defeating 4.
The lesson to be learned here is that third hand should take a moment to get an overview of the deal, not just the suit partner has led, before playing to the first trick.
