Can anyone explain this defence

[thepossum]

Hi all

 

I was unsure about going to 5Hx which double dummy should go down 3 tricks against a vulnerable game

I was surprised to make this. Especially when East ducked the second trick to my King singleton

Is that really the percentage defense? Obviously not on the layout but in a sim

 

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[LBengtsson]

The only explanation I can give is 'LOL' There is no other word that can be used.

[smerriman]

Especially when East ducked the second trick to my King singleton

Is that really the percentage defense? Obviously not on the layout but in a sim

To a robot, yes; West needs to retain the lead in order to send another club through, which results in an extra trick much more often than it costs, given the high likelihood of West having the K. E.g.:

 

[hv=https://www.bridgebase.com/tools/handviewer.html?s=s4hkqj8653d6ct976&e=sa965h74dkqt874c8&n=sq3hat9dj532cq542&d=n&a=pp3hp4hpp4spp5hppxppp&v=e&p=ckc2c8c7sjs3]400|300[/hv]

[pescetom]

I'm puzzled about West's switch to spades at trick 7.

Not sure it could ever gain, it certainly costs on the actual diamonds layout which seems consistent with the auction and agreements.

[smerriman]

I'm puzzled about West's switch to spades at trick 7.

Not sure it could ever gain, it certainly costs on the actual diamonds layout which seems consistent with the auction and agreements.

Agree it can never gain. But the actual layout isn't possible, given South has promised a max of 9 HCP with the opening bid, so can't have the ace of diamonds. Of course, East denied an opening hand too. But if you swap the positions of the Q and A of diamonds, then it then technically falls within the described ranges, and it doesn't matter what West returns.

 

Can't easily replicate this on the old version of GIB since BBO heavily changed the definitions of preempts, but I suspect it's a mix of this (excluding most hands where South has the A) and the bug where it miscalculates double dummy on a proportion of hands to cause it to make the worst play.

[thepossum]

I double checked the tourney and there were quite a few tables that didn't make. It's true that the decision on Trick 2 is not totally fatal

Curious why some people get what appears to be pure luck.

Almost everyone did pre-empt though 2 or 3

[kenberg]

A comment on defense that leads to a comment on declarer play.

 

Imo, after the lead of the club Kand, when dummy hits with the Qxxx, 3rd hand has only count to give, not attitude. When the K holds the trick, 3rd hand knows where the A is (he pretty much knew from the lead of the K).

Declarer should follow with the T, not the 7. Since E would, or at least should, play the T if he held T8, the play of the 7 allows W to continue with a small club. E ruffs, assumes the small club asks for a D, leads the K of D, ruffed, now when a spade is returned E has an easy play of hopping up with the spade A and cashing the Q of D.

 

 

If, at T1, declarer plays the C T, it gets tougher. Someone was dealt a stiff, but who?

 

Bots are not that great at the "What will pard think" aspect of the game. W wants E to think "pard wants a D ruff". But if W is worried about continuing with a small club after declarer plays the T at T1, that message gets a little tough to send.