The Vienna coup is an unblocking technique in contract bridge, so called because it was first recorded in Vienna in the days of whist, used to avoid problems when executing an automatic squeeze.
| ♠ | A J | ||
| ♥ | A | ||
| ♦ | — | ||
| ♣ | 2 | ||
|
N |
♠ | K Q | |
| ♥ | K 4 | ||
| ♦ | — | ||
| ♣ | — | ||
| ♠ | 4 | ||
| ♥ | Q 2 | ||
| ♦ | — | ||
| ♣ | A | ||
On the play of the ♣A East is squeezed, but can escape by throwing a small heart. Although the ♥Q is set up, there is no way back to the hand to cash the winning heart.
| ♠ | A J | ||
| ♥ | — | ||
| ♦ | — | ||
| ♣ | 2 | ||
|
N |
♠ | K Q | |
| ♥ | K | ||
| ♦ | — | ||
| ♣ | — | ||
| ♠ | 4 | ||
| ♥ | Q | ||
| ♦ | — | ||
| ♣ | A | ||
However, if instead, the ♥2 is played to the ♥A, East is squeezed when Declarer next leads the ♣2 to the ace.
If East discards the ♥K, declarer cashes the ♥Q discarding the ♠J and leads to the ♠A. If East discards the ♠K or ♠Q, declarer cashes the ♠A and ♠J.