[Jinksy]

I've just played a daylong, where a robot did something very weird, but presumably a report is little use without a hand - and apparently I don't see records of daylongs? If it's stored somewhere, see if you can access a board I played about 20 minutes before posting this in said daylong - board 6, 2N - 1

The entire defence was surreal, but tricks 8 and 10 were a particular kind of special. Maybe my over-heavy WJS confused it? But those were still some drastically bad decisions.

[steve2005]

Gib makes ridiculous plays all the time.
Recently i was defending NT we had bid clubs, but Gib led diamonds.
dummy was void in diamonds and Jxx in clubs and something in majors i can't remember.
Declarer Gib pitches JC. crazy it's a potential stopper.
Now turns out it didn't matter (but Gib can't know this for sure), but goodness pitch a small club if you pitch a club.

[smerriman]

---

Yeah, just standard GIB behavior after you make a 'crazy' (from GIB's perspective) bid really. As usual, it assumes you didn't lie, and bases everything on that assumption.

[cloa513]

 smerriman, on 2018-January-18, 00:29, said:

---

Yeah, just standard GIB behavior after you make a 'crazy' (from GIB's perspective) bid really. As usual, it assumes you didn't lie, and bases everything on that assumption.

Except the play is bad even if you told the truth.

[steve2005]

Did Gib, listen to the bidding?
You bid ♥! If you have KQ♥ and an entry, continuing ♥ will put down big.
East bid ♦. If switching why switch to ♦?
Goodness even a small club only needs partner to have 2♣ and entry.
Diamond lead is foolish even though still possible to beat with a club switch but how do you figure that out?

[johnu]

Excellent technique by North to avoid the club throw in for the fatal spade end play The switch to a diamond at trick 2 was also excellent. If South wanted a heart return, he should have bid diamonds, clubs, or spades. Really, this is Bridge [-]101

[Jinksy]

 cloa513, on 2018-January-20, 03:25, said:

Except the play is bad even if you told the truth.

Yeah, this seems like a salient point for the robots - humans just aren't always going to have the hands the robots think they should for the bidding (to say nothing of vice versa!), so they shouldn't be making provably bad plays just because they think they can prove a contradiction.

[johnu]

 smerriman, on 2018-January-18, 00:29, said:

Yeah, just standard GIB behavior after you make a 'crazy' (from GIB's perspective) bid really. As usual, it assumes you didn't lie, and bases everything on that assumption.

Even though the 2♥ is too strong for GIB's definition, at trick 2, GIB can't possibly know you have something like,

---

so why would it not return a heart???

Later on, there is no way for declarer to take a club trick barring a brain aneurysm by North. There isn't any South hand where throwing away club tricks is the best line of play.

[steve2005]

 johnu, on 2018-January-20, 13:28, said:

If South wanted a heart return, he should have bid diamonds, clubs, or spades. Really, this is Bridge [-]101

Yes how many NT contracts have been allowed to make as Gib didn't lead or return your suit.
Safe leads are fine but I've seen 3NT where Gib had opening lead and got in 3 times. It lead all four suits in turn.
How can you beat 3NT doing this?

[steve2005]

North's braindead defense is just unacceptable, even if this was not with the advanced robots.
North Gib pitch's A♣ and then ducks K♣ when defense has rest of tricks.
Humans who took up the game today often will defend better than Gib.

[smerriman]

 johnu, on 2018-January-21, 19:38, said:

Even though the 2♥ is too strong for GIB's definition, at trick 2, GIB can't possibly know you have something like,

---

so why would it not return a heart???

If GIB thinks you have that hand, a heart return and a diamond return are equivalent double dummy. So that isn't a good example for proving your point (though it does suggest a low club) - any others?

That real issue is that diamond is probably fine double-dummy (just like it was in the original hand), but requires partner getting the switch right (had to switch to a club). Double dummy analysis is the crux of any robot program though, so I'm not sure how that's avoidable.

[steve2005]

 smerriman, on 2018-January-22, 13:23, said:

If GIB thinks you have that hand, a heart return and a diamond return are equivalent double dummy. So that isn't a good example for proving your point (though it does suggest a low club) - any others?

Goodness partner can easily have KQ♥ and an entry leading heart is just obvious.
Leading a diamond is completely double dummy and a lot of hands will just be plain silly.
The only real other try is a club.

[smerriman]

 steve2005, on 2018-January-22, 18:09, said:

Goodness partner can easily have KQ♥ and an entry leading heart is just obvious.

I'm afraid that's impossible as well; East has promised a heart stop. Yes, I know it shouldn't assume so much from the bidding, and I've posted about that flaw many times, but it does.

*Given the bidding assumptions*, you're still yet to find a hand where a heart is obvious It's harder than you think.