Another 3NT

[kgr]

IMPs[hv=pc=n&s=sa62h743daj82ck98&n=sj98hkqtdkqt9cqjt&d=e&v=0&b=14&a=1n(9-11)p2h(transfer)p2sppdp3s(asking%20stop)dpp3nppp]266|200[/hv]

You play 3NT after East opened 1NT (9-11 HCP) and West transferred to spades.

West leads ♠4.

Do you play small or high from dummy?

[mgoetze]

This doesn't seem particularily controversial? I mean, first of all, we have 26, if East has 9, then ♠KQ is the absolute maximum West can have in terms of high cards. East could have 10 or West could have some random Jack and then ♠KQ is already impossible, so East is a big favorite to have at least one spade honor. Meanwhile West has 2/3 of the spade cards we haven't seen, so he is favorite to have the 10. Seems pretty obvious to me to play the 8 or 9.

[kgr]

This doesn't seem particularily controversial? I mean, first of all, we have 26, if East has 9, then ♠KQ is the absolute maximum West can have in terms of high cards. East could have 10 or West could have some random Jack and then ♠KQ is already impossible, so East is a big favorite to have at least one spade honor. Meanwhile West has 2/3 of the spade cards we haven't seen, so he is favorite to have the 10. Seems pretty obvious to me to play the 8 or 9.

You didn't mention West's DBL. Do you consider it unimportant?

[nige1]

rubbish deleted

[whereagles]

Small.

 

You're playing for LHO with KT+ or QT+, which is roughly twice as likely as KQ+.

[Fluffy]

Small.

 

You're playing for LHO with KT+ or QT+, which is roughly twice as likely as KQ+.

Not fully accurate, if ♠J is wrong we have a backup ♥J finesse while if ♠9 is wrong there is no back up finesse since the ♥J must be wrong. So 1/3 or 1/2 vs 2/3 is equal in theory.

 

We could count all honor combinations.

 

-♠KQ jack wins

-♠K low wins 4/5 times when ♠10 is onside

-♠K + ♥J anything wins

-♠Q + ♥J anything wins

-♥AJ anything wins

-♥A Anything wins except if they duck ♣Axxx and manage to score 2♠, 2♣, 1♥, but this position still makes no sense given the double.

-♣A low wins, but double makes no sense

-♣A + ♥J anything wins

 

 

I am probably missing some combinations, but so far the jack looks a tiny bit better asuming the double cannot be done on ♠10xxxx.

 

The problem is that we are assuming 2 things that don't need to be true: double shows a willing to get a spade lead, and RHO will never upgrade or downgrade into the 9-11 range. These assumptions are probably far from certain, so playing low will probably be better in practice.

[kgr]

Thank you all.

RHO had ♠Tx and all other honors in ♥♦♣.

I played ♠9 and ended -1.

[Free]

If LHO has ♠KQ he can never cash them. All we have to do is duck the first trick. Small is obvious. When RHO wins ♠T and continues with the ♠K we can duck again, blocking the entire suit.

[kgr]

If LHO has ♠KQ he can never cash them. All we have to do is duck the first trick. Small is obvious. When RHO wins ♠T and continues with the ♠K we can duck again, blocking the entire suit.

Not so obvious. If LHO has ♠KQ then RHO has the other honors and only 8 tricks can be made if you duck the first trick.