Explanation of T/O-double

[thorvald]

The south hand seems to strong for a direct 4♥ bid, but it seems that after a T/O double the robot will not understand that South has a hand with long ♥s

 

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So after a cuebid of 2♣ in North I found it impossible to get to ♥s as T/O is defined as 3-4♥ and 3-4♠s

 

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I think the 3-4♥ from T/O-Double is wrong as it can be any 18+ hcp hand

[helene_t]

Yes that's an annoying issue.

 

GIB doesn't quite understand that a t/o double can also be 18+ almost any shape. It's a bit inconsistent because sometimes it will pass your second bid with shortness in your suit and length in another suit, but generally it's good advice not to double without support for all unbid suits, or at least the unbid majors. With this hand I think it's practical to overcall 4♥. You can also start with 2♥.

 

FWIW I wouldn't double with this hand opposite a human partner, either.

[smerriman]

This is a well known GIB flaw. GIB can handle offshape doubles if the opponents stay silent, and partner makes a simple suit bid.

 

But if partner shows strength like here, or the opponents compete, none of the followup are programmed correctly, each of them locking in the classic takeout double definition. So you basically have to avoid using them as much as possible.