Hey Gib, Ever Hear Of Lightner Doubles?

[barmar]

This was the first board of a disastrous round (-4950) of MBT.

 

[hv=d=n&v=n&n=s8642hjt3dqj84ct8&w=sk5hk8dt63ca76543&e=st73hadak9752ckq2&s=saqj9hq976542dcj9]399|300|Scoring: Total Points

--- P 1♦ 1♥

2♣ P 4♣ 4♥

P P 4NT P

5♦ P 6♣ Dbl[/hv]

 

I was South, I made a very clear Lightner double. All GIB has to do is lead a ♦ like I asked. I ruff, cash ♠A, and they're down. But NOOO, it leads ♥J. Later, when declarer leads a low ♦ towards dummy, it splits its honors, making it easy for declarer to pick up the suit.

[MomoTheDog]

Lighter doubles are not part of GIB's CC.

 

http://online.bridgebase.com/doc/gib_system_notes.php

[sceptic]

If you had spent 5 minutes chatting to your partner and agreeing a system and some conventions, you would not have this problem. A quite common fault amongst pick up partners in the MBC:(

[helene_t]

But Wayne, I have spend more than five minutes telling GIB what I play, I took his silence as affirmative, yet I still have this problem ????

[awm]

It is perhaps worth mentioning that splitting honors here seems like a very poor play. How could it ever win?

 

This is actually something I've wondered about GIB for a while -- there are fairly frequent defensive plays where your choice of card will virtually never make a double dummy difference in the result, but where one play gives declarer the chance to go wrong and the other doesn't. Splitting honors here is a simple example. As I understand it, a lot of GIB's play and defense is done by simulating many hands double-dummy... so perhaps this is a weakness in that approach.

[barmar]

Yes, I think that's a problem with its defense. Sometimes it will help declarer take a finesse by sticking in the missing card, or even lead it, because it knows from its double dummy analysis that declarer is going to take the finesse. While there are certainly times when this is necessary to unblock, I think it does it many times when this isn't needed.

 

BTW, I think it's only fair to praise GIB for proper restraint in a hand in a later MBT. The opponents got to 7♠ by East in an auction that was again crowded by my preempt. GIB N held ♠QJTxxx. How many of us would be able to resist doubling? But GIB didn't double, and we easily set them quite a few (East had opened with 98xxx and West supported with ♠AK and ♣AKQTxxx). A double might have pushed them to 7NT, which makes on a finesse (again my preempt was in a Q-high suit, and EW had AK).

[NickRW]

As I understand it, a lot of GIB's play and defense is done by simulating many hands double-dummy... so perhaps this is a weakness in that approach.

That is quite definitely a weakness in the approach. It doesn't take account of the fact that the other side doesn't know what you know.

 

It may take quite a bit of rejigging GIB to alter that behaviour though!

 

Nick