Oh, I know you've played the convention. No, I mean played the hand in Stayman. My partner did so yesterday evening:
Having recently switched to a weak NT structure, we had been practicing escape sequences if the NT bid got doubled. If West had doubled, 2D by partner would be a sign-off. As you can see, West did not double, but I was well and truly engrossed into escape sequences. Hence the pass of partner's Stayman bid. Partner played the silly contract rather well, but 2D making 7 was worth zero match points.
But there are some days when the luck is with you. We did not have a spectacular game, but still ended up with 56% and in second place. Here's one instance of luck being with us -- they got to 5C on this sequence:
Sitting West, and holding my cards, what do you lead?
I decided to lead a low trump. Partner contributes the 9 and declarer wins with the 10. Declarer now advances the 3 of hearts. What do you do?
The play of declarer's singleton was suspicious -- it is almost as if declarer was trying to set up a bunch of discards. So, I took my Ace of hearts and put down the Ace of spades. Partner encouraged this, and we cashed three spades. 5C down 2 was worth all of the matchpoints. This was the full deal:
Finding the defense to 5C was far easier and on days when Lady Luck is with you, the defenses you are called on to find are easier.