But of course, in duplicate (in my case pairs MPs) there's often a MPs value, positive or negative, in a passed hand.
Faced with this after three passes, playing Acol 12-14 1NT, N-S vul:
I didn't take too long deciding to pass out!
This meant that we had plenty of free time before the next round was called. One of my opponents - an experienced player - told me that statistically I chose the right option to pass on 11 with no biddable suit. More often than not, a light opening in this situation goes down.
But as it turned out, of the eight tables, six passed and two played - and made - 1NT to E-W. So not so good for us after all!
I had no agreement with partner to open 1NT on 11, I suppose I could have chanced it knowing that she couldn't have more than 11 herself so was unlikely to raise. And the odds were, we were likely to have more HCP than the opponents, so 7 tricks is a reasonable bet.
Should I add "1NT = 11-14 if fourth in hand" to my CC? Seems like there may be some value in it.