Claim ruling

[Echognome]

The reason I find the claim of 12 tricks damning is that it implies that declarer did not see the line for 13 tricks at the time of the claim.  To me, that says it should certainly be rational for him to find a line to take only 12 tricks.

What if declarer had claimed 11 tricks.

 

Would you then award him only 11 tricks on the basis that he could not count to 12?

No, because to me it would be careless to draw an extra trump or discard diamonds instead of hearts. It would be irrational not to take 12 winners. It's where I draw the line. I'm open to other opinions of course. It's just how I interpret the laws.

 

Edit: Ultimately, we have to decide what plays are careless or inferior, but NOT irrational. The Law says they exist. Perhaps it would be better if we were given some concrete examples of what falls under such plays. Without further guidance, I give my interpretation above.

[Joe de Balliol]

Right, I've thought this one through, and here's my answer:

There is no line of play that is both normal and rational that will allow declarer to come to fewer than thirteen tricks.

 

Drawing an extra trump immediately would be irrational, as he does not know the clubs are splitting.

Playing on clubs than playing on trumps is abnormal.

In the situation where he has something like ♠x♥xx♦x♣void in dummy and ♠x♥Ax♦void♣x in hand, it's clearly irrational for him to pitch a diamond.