[Bbradley62]

baraka, on 2015-July-04, 07:16, said:

Played ACBL instant tournament this morning. Crap ! Robots defend better today then some years ago and you can get some very bad results simply because of that. It's unfair and never again will I get involved in this crap !

(1) It's my understanding that the baseline hands were not played "some years ago", but "some months ago";
(2) I don't think the programmers have made any specifics changes to improve GIB's defense.

[baraka]

1eyedjack, on 2015-July-04, 11:04, said:

Change is on the way.

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Out of 15 players, 12 where in 6NT including me. All the other players had a small heart lead giving away the contract. Not me. 3 of spades ! Not very friendly ! It blows quite a hole in your game ! How can that be changed without brigning back the old bidding bugs also ?

[barmar]

Bbradley62, on 2015-July-05, 04:47, said:

(1) It's my understanding that the baseline hands were not played "some years ago", but "some months ago";
(2) I don't think the programmers have made any specifics changes to improve GIB's defense.

Some are months old, some are years old.

While we haven't made many changes specifically to GIB's defense (except if it doubles a grand slam, it should now cash the ace that was its reason for doubling), its defense is very dependent on its bidding database, since it uses simulations with hands that are consistent with the bidding. So changes in the bidding rules will have an effect on its defense, since the hands it simulates with will change.

[baraka]

barmar, on 2015-July-05, 10:09, said:

So changes in the bidding rules will have an effect on its defense, since the hands it simulates with will change.

So we will always be prone to some unhappy mishaps !

[Bbradley62]

So, the difference here are probably:

• different "seed" on different dates. I think this has been discussed. Any way to save that info?
  
• Declarer's preference for a finesse rather than a squeeze.

[1eyedjack]

baraka, on 2015-July-05, 06:11, said:

---

Out of 15 players, 12 where in 6NT including me. All the other players had a small heart lead giving away the contract. Not me. 3 of spades ! Not very friendly ! It blows quite a hole in your game ! How can that be changed without brigning back the old bidding bugs also ?

The definition of "on the way" as in "change is on the way" includes the inference "not here yet". So, if change is "not here yet" it should not be much of a surprise to continue to find examples of what has yet to be changed.

If you read other threads you will note that one of the reasons that you now have to log into myhands is to shore up a security weakness in preparation for allowing instant tourneys to use a current version of gib at the other tables. But this is a work in progress.

[barmar]

Bbradley62, on 2015-July-05, 11:27, said:

So, the difference here are probably:

• different "seed" on different dates. I think this has been discussed. Any way to save that info?
  
• Declarer's preference for a finesse rather than a squeeze.

The robots used in tourneys always use the same seed, it's not based on the time, so there's nothing to save.

I'm not sure what you mean by the second point, the robots don't have any particular preference one way of the other.

[Bbradley62]

barmar, on 2015-July-05, 21:18, said:

The robots used in tourneys always use the same seed, it's not based on the time, so there's nothing to save.

I'm not sure what you mean by the second point, the robots don't have any particular preference one way of the other.

So, if this auction yielded a heart lead at all the "baseline" tables and a spade lead during the recent replay, there was a programming change in how GIB chooses his opening lead? I expect this to be due to different simulations.

The preference was that of the human declarer, not of a GIB.

[barmar]

Bbradley62, on 2015-July-06, 19:11, said:

So, if this auction yielded a heart lead at all the "baseline" tables and a spade lead during the recent replay, there was a programming change in how GIB chooses his opening lead? I expect this to be due to different simulations.

As I said, simulations are dependent on the bidding rules. So if the auction is the same, but the meanings of any of the bids in the auction changed between the two versions, that will change the hands that are used in the simulation, even though the seed is the same. And that could cause it to make a different opening lead.

Quote

The preference was that of the human declarer, not of a GIB.

If the human plays differently, that will change how the robots defend. But I guess that's the point you were making.

I thought we were trying to explain why the robots did something differently at a point where everything leading up to it seemed to be the same.

[steve2005]

baraka, on 2015-July-05, 06:11, said:

---

Out of 15 players, 12 where in 6NT including me. All the other players had a small heart lead giving away the contract. Not me. 3 of spades ! Not very friendly ! It blows quite a hole in your game ! How can that be changed without brigning back the old bidding bugs also ?

There is an automatic squeeze against west for 6N+1 on any lead if anyone cares?!

[Bbradley62]

steve2005, on 2015-July-12, 21:53, said:

There is an automatic squeeze against west for 6N+1 on any lead if anyone cares?!

See post #25.

[barmar]

Since a few days ago, instant tournaments should be using only hands played with the current version of GIB (unless you've somehow managed to play all of them, then it will fall back to the previous version).

Whenever we deploy a new version of GIB, it will take a couple of weeks for us to collect enough tourneys to start using them as the basis, so during that period it will continue to use the previous version. But it should never get older than that.