Taking advantage of an opponent's error

[ArtK78]

[hv=d=s&v=n&n=sjt7hajdkt985cqt2&s=s98hkq432d4cak765]133|200|Scoring: XIMP

1♥ - (P) - 1NT - (2♠)

3♣ - (3♠) - 4♥ - All Pass[/hv]

 

LHO leads the ♠K and continues the suit to partner's Ace. At trick 3, RHO continues with the ♠Q.

 

Your move.

[blackshoe]

My immediate reaction is "pitch a diamond".

[TylerE]

Ditto

[ArtK78]

Yes.

 

Unfortunately, there is no way to pose this problem into a format where the fact that it is a problem will not wake up anyone sleepy enough not to realize that ruffing could be wrong.

 

My semi-pickup partner (we have played a number of sessions, but I have never met him in person) ruffed small, got overruffed and lost the ♦A for down 1. Pitching a diamond is about 95% correct. There is a lie of the cards where pitching a diamond is the only way to go down (and you would not have gone down had the opponents cashed the diamond before the 3rd round of spades). Consider this layout:[hv=d=s&v=n&n=sjt7hajdkt985cqt2&w=skxxh98dqjxxxcjxx&e=saqxxxht765daxcxx&s=s98hkq432d4cak765]399|300|Scoring: XIMP[/hv]

 

If you pitch a diamond, a fourth round of spades will create a trump trick for East.

 

However, in light of the opening lead and subsequent play, this is an unlikely construction of the opponents' hands. In real life, the spades are 6-2. LHO is 2-4-5-2. If you pitch a diamond, you can handle any play at trick four.

 

RHO could have (and should have) beaten you by cashing the ♦A before playing the third round of spades. But the opponents do not always defend properly. And you must take advantage of their mistakes. My partner was asleep at the wheel on this one. He probably would have gotten it right if it was posed to him as a problem.