[lycier]

Now look at my hand :

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Lead ♥10, the result is 4♠N=
Gib,very very well done, especially wonderful endplay.
Some people have looked down on Gibs, and thought it is a weak player in the past.
Now,is it really weak?
I would like ask everyone to share my feedback throught my survey.

- See my traveller :



- From first hand to 9th, its classic sequences are same as my hand.
- 10th hans :

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Result : 3♠N= , north player only got 9 tricks. the blame is human

- 11th hand :

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Lead [diamonds7, ]Result: 2♠N+1
The blame probably is Gib. However I know this issue had nothing to do with Gib CC, there are two main reasons - one is a unknown disconnection issue, another probably is Gib bidding server issue, fair to say, this issue is non-technical.

- 12th hand

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Result : 2♠N+1
The blame is human

- 13th hand

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Result : 2♦N=
The blame is human

- 14th hand

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Human is a declarer, the result is 4♠N-2
Very bad playing, the blame is human.

-15th hand

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Result :5♥S-3
Rediculously playing, the blame is human.

-16th hand

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Human is a declarer, the result is 4♠N-3
Very bad playing, the blame is human.



The final results on the sample of 16 hands
Gib :
1- There are 9 hands with 4S contract, bid and make it so well.
2- There is one hand - an unexpected failure on the robot.

Human :
1- There are 5 hands without 4S contract, bid rediculously, the blame is human.
2- I never found any human players can play this hand so well.



My conclusion :
1- Bidding: Robot zero errors, human made five times mistakes.
2- Declarer playing :
Robot : well done in from first hand to 9th.
Human : no good hand, there are five hands in total.
3- Gib is not a weak player. obviously in fact far more stronger than random human players on BBO.
4- Gibs are gradually becoming more and more smarter, and Gibs are improved its skill rapidly day in day out.

[1eyedjack]

A few comments.

Starting from the beginning: the bidding. I note that at different tables GIB North made different decisions about the value of its hand after a 1S-(p)-2S-(p)-? start, At your table GIB bid 4S. At others it was content with a game try. I don't have a strong opinion. I suppose it is borderline. Suffice it to say that 4S is a pretty poor spot on the given hands, in my view. Maybe you disagree. But we do not criticise GIB for borderline judgement calls. Oddly, at table 11 North did not even try for game after the 2S raise but just left it in 2S. Successful, in terms of double dummy par, but I personally would rate that as a gross underbid. Not borderline.

Then the choice of opening lead. GIB normally avoids leading from broken sequences when it has an alternative. Not that the Heart lead was fatal because it was a broken sequence. As North has AK doubleton it did not cost on that score. It only cost because of the later exposure of his partner to an endplay, where a "safe" Club lead would have guaranteed defeating the contract. But we do not criticise GIB for borderline opening leads.

Then declarer's choice of H:J from dummy at trick 1. What is that all about? East could just as well have led from H:T987 as it might from H:QT98, with the H:Q then dropping in two round with the potential for a Club discard which yes an opponent might ruff but with a natural trump trick. Also to play the J at trick 1 and then overtake in hand rather telegraphs declarer's Heart holding. Playing low at trick 1 would only provide declarer with a tiny extra edge, but I think it should at least preserve that edge.

I think that GIB West quite seriously mis-defended by leading S:A at trick 7. Either low Spade or Diamond Q beats the contract, and I think that West should predict the endplay just as North did. North really had no alternative play to make by trick 10/11. In my view North's most impressive decision was the way it tackled the trump suit on the first round. Humans are rather loath to commit the King when there is a lower finesse to take.

I think that criticism of human North on hand 10 may be misplaced. This is IMP scoring and he is in 3S not 4S. His primary obligation is to make his contract, which he did, at the possible expense of an overtrick. He incurred a different lead from your table, which picks up the Diamond suit for just one loser. Possibly this changes the dynamics of how best to play on trumps the better to ensure 9 total tricks. I don't know the answer with confidence. I do know that we are not comparing like with like.

On table 14, the human declarer received a killing Club lead and had no chance to make the contract. He went one more off than necessary, mainly because of his choice of trump play. Possibly that was poor, but it could have worked better on a different lie. "Very bad play"??

I don't see much evidence in this forum that contributors consider GIB to be a bad player. It is an impression that can be received by the fact that the only hands posted here are ones where GIB makes absurd decisions (or bidding descriptions are absurd). You being an exception, few posters are motivated to post hands that extol its virtues, as they are generally motivated to try to improve GIB by removing its greatest flaws, and posting hands where GIB gets it right is superfluous to that end.

As to your final list of conclusions, I challenge your conclusion that GIB made no errors. West was GIB at your table and West definitely erred. I forgive East (also GIB) the opening lead and the play of H:J at trick 1. I would rate North's decision to pass 2S on table 11 as being an "error", notwithstanding its potential success. Or to put it another way, either 4S or pass of 2S is an error. Possibly both, if you favour a game try, but at least one of them is wrong. Take your pick

[lycier]

Facing to responding 2♠, I think all the experts would rebid to game, pick 4♠ or 3nt as a final contract if play 2/1 bidding system.

[manudude03]

I think it's also worth noting that West in the initial hand misdefended it. When it wins the diamond, a fourth diamond kills the contract (East will switch to clubs when he wins his trump).

edit: I missed that jack had already pointed it out. I think leading out the ace of trumps is terrible though, it pretty much forced the endplay line to happen.

[1eyedjack]

The declarer play is not without interest.

In his choice of trump plays, GIB did well to rise with the Spade King on the first round, as already mentioned.

What I neglected to mention was that to play on trumps at all at trick 4 costs the contract, even getting the trumps right.

I noticed that a club lead according to GIB is the only opening lead that guarantees beating the contract, and yet later observed that West had an opportunity to defeat it. That can only come to pass if declarer has chucked a trick at some point, and that point came at trick 4, when to stay on track he has to continue Diamonds (finessing if West fails to split).

I think that it is unlikely that finessing the diamond is the best single dummy play. Whether playing a second diamond at all (before touching trumps) is the best single dummy play I am less sure about. GIB only tells us the double dummy line. But if you think it right at single dummy to continue Diamonds, then it takes a bit of shine off a claim that GIB North played flawlessly.