Jump to content

GIB and restricted choice


steve2005

Recommended Posts

Say you are missing QJ in suit and have AKT9 and combined 8-9 cards in the suit. Also, assume no entry problems etc.

 

Normally if opponents play Q or J after you play Ace it is a 2-1 favourite to finesse next time suit is played.

 

Theory

If GIB defender has QJ doubleton it will always play the Q.

 

So, if Gib plays the Q restricted choice doesn't apply and you have normal odds for that suit.

However, if Gib plays the J it is now a 100% play to finesse as GIB won't have QJ.

 

Is this theory correct?

  • Upvote 1
Link to comment
Share on other sites

According to GIB system notes it randomises its card when it has equivalent cards in a doubleton, though there's other stuff in the system notes that is 100% provably wrong. I don't have evidence either way, though I don't recall seeing such a pattern. Could do some digging to find out.
Link to comment
Share on other sites

I haven't done a study but have a large sample of games to base my guesstimate on, and it seems random to me. I'm sure that GIB has held QJ a few times in this situation for boards I've played. However, it is almost always a top and bottom proposition to take the finesse since more than half of most fields don't play RC. I usually go for the top since it would bug the crap out of me if I wimped out and it worked.
Link to comment
Share on other sites

I think you might be right. A while ago I did some probability analysis on 2000 GIB challenge hands - once you restrict it to one of West/East holding QJ and someone playing a high honor earlier in the trick, that reduced it to a tiny sample of 8, but 8/8 of those occasions GIB dropped the queen.

 

That must have been deleted from the code along with the other notes about signalling etc. That is awful.

 

Perhaps spreading the news about this might be the catalyst needed to get BBO to actually do something about the code (at least opening it up to others), rather than say it's too hard to fix anything but bidding holes.

  • Upvote 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...