System change after double

[thorvald]

[hv=pc=n&s=sa62ha9864dqct652&d=n&v=0&b=1&a=1np2dp2hp3c]133|200[/hv]

 

On this hand the bot transfers to ♥, and then bid a gameforcing 3♣ after partner opened 1N, and that seems pretty normal.

 

If LHO double the 2♦ bid, then 3♣ is no longer forcing, but instead 8- points.

 

[hv=pc=n&s=sa62ha9864dqct652&d=n&v=0&b=1&a=1np2dxpp3c]133|200[/hv]

 

The Bot might downgrade ♦Q, but still a large difference between the two bids

 

I still haven't tested if it makes a difference if opener accepts the transfer.

 

And also worth to test if it makes a difference if the hand is a passed hand

[HardVector]

[hv=pc=n&s=sa62ha9864dqct652&d=n&v=0&b=1&a=1np2dp2hp3c]133|200[/hv]

 

On this hand the bot transfers to ♥, and then bid a gameforcing 3♣ after partner opened 1N, and that seems pretty normal.

 

If LHO double the 2♦ bid, then 3♣ is no longer forcing, but instead 8- points.

 

[hv=pc=n&s=sa62ha9864dqct652&d=n&v=0&b=1&a=1np2dxpp3c]133|200[/hv]

 

The Bot might downgrade ♦Q, but still a large difference between the two bids

 

I still haven't tested if it makes a difference if opener accepts the transfer.

 

And also worth to test if it makes a difference if the hand is a passed hand

I'm willing to bet that a XX forcing opener to bid 2h followed by 3c is forcing.

[thorvald]

I'm willing to bet that a XX forcing opener to bid 2h followed by 3c is forcing.

 

You are probably right, but anyway the bot then downgrades the hand - Interesting

[smerriman]

I'm willing to bet that a XX forcing opener to bid 2h followed by 3c is forcing.

GIB never redoubles, the basic bot will bid a non-forcing 3♣ even with an ace extra (while the advanced robot would just bash out 4♥ and hope for the best).

 

GIB has a set of rules telling it how all of the continuations are defined after partner accepts the transfer with 2♥ (and separate rules after a superaccept). This section doesn't include any rules for what to do if partner *passes* the transfer (despite the fact North has its own rule saying pass with 2 hearts, accept with 3 hearts).

 

So as with most competitive auctions, it falls back to a set of default rules that have nothing to do with transfers. There is a rule which says in general auctions like this, a new suit at the 3 level shows game forcing values. However, it has another rule that says if you're forced to bid and have no fit, a cheap new suit doesn't show anything. It combines the two, making the club bid but unable to promise any points.

 

Often fixing robot bugs is difficult because a slight change can break a bunch of other sequences. This one would be pretty easy to fix by adding a few new rules for continuations after this double that promise strength, after which default rules for later bids will work fine.