A Grosvenor Coup is defined as: "A defender deliberately making a clear error, giving declarer a chance that he will refuse to take because he expects rational defence". I suppose that West's activities on this deal came under that heading. Anyway, I fell for it.

North opened 1NT (ostensibly 12-14 points), East bid 2#, and I (South) doubled. West retreated to 2! and, after two passes, I plunged to 44 against which West led the #2. I won East's king with the ace, crossed to the 4K and ran the 4J successfully. Yes; 4J was allowed to hold!

There were now 11 tricks in sight, but this was a pairs competition and 12, I thought, would be even nicer. So I crossed to a top club, led a diamond, and ducked when East played the ten. The !J came back and, after I had won with the ace, my route was clear. I crossed to dummy's remaining high club and took the marked finesse of #9. The plan, of course, was to cash the #A (discarding dummy's remaining heart), ruff a heart, and claim.

There was a hitch. West ruffed the #9 with a totally unsuspected queen of trumps and the defenders cashed a heart trick to hold me to the 10 tricks with which I had started (after misguessing the spades).

Did West foresee all this? No, he simply pulled the wrong card.