[Natali_]

Natali 28 - Ranmit 4

[barmar]

barmar - diana_eva 43 - 27
https://webutil.brid...162146&u=barmar

[barmar]

heart76, on 2018-December-19, 16:00, said:

You have my full respect and appreciation for the work you do. However, FWIW if I were the TD I'd take the consequence of it and have a policy to amend the results of those few horrendous outliers - not to be misunderstood, this of course applies to any player in tournaments where the blunder counts.

We've tried to fix some of the worst bugs -- it used to double 6NT with 2 cashing aces, then not lead them! (Presumably it envisioned a small chance to get a 2nd undertrick if it didn't set up declarer's kings, and not enough of the simulated hands had 12 tricks available in the side suits.)

This particular problem is harder. It's not so obvious when the results of the simulations need to be ignored. And we can't look at the result at the other table to ensure that it plays the same way, to prevent

And if you think the situation you raised is bad, how about all the times that it leads its singleton trump king, which it probably would have won when declarer takes a finesse? This is a consequence of the use of double dummy simulation -- it "knows" that declarer will play for the drop instead of finessing. I've considered whether we should put in another special case to block this, but there's a reason why it thinks a trump lead is best, and in many cases it doesn't actually give away a trick (if the ace is over the king you were going to pick it up anyway, and if partner has the queen there's no finesse.), and we have to be careful when overruling these decisions.

Everyone who plays robot tourneys learns that things like this happen from time to time; the underlying design that uses DD simulation and statistical analysis has some obvious flaws. Sometimes you're the beneficiary, sometimes you're the victim. If things like this really bother you, you should stay away from GIB.

Our work on improving GIB is primarily focused on fixing problems in the bidding database. We actively welcome reports on these issues.

[shuba]

SHUBA :
- Natali +21
https://webutil.brid...5257370&u=shuba
- GIB -12
https://webutil.brid...5257370&u=shuba
- Cyrenman +12
https://webutil.brid...5273394&u=shuba

[cyrenman]

Group B cyrenman 32 - 31 GiB
http://webutil.bridg...aeb4-1545331203

[Povratnik]

Group C

Povratnik 35 : 10 ye17

Boards

[Mkgnao]

pio_magic-Mkgnao 19-45

https://webutil.brid...172627&u=mkgnao

[gordontd]

Two of my games seem to have been missed off the spreadsheet - #34 & #39 above.

[smerriman]

gordontd, on 2018-December-20, 17:19, said:

Two of my games seem to have been missed off the spreadsheet - #34 & #39 above.

Thanks - fixed a glitch in my script.

[twisterrz]

https://webutil.brid...=twisterrz#row-

twisterrz 38-41 mlbridge

[mlbridge]

barmar, on 2018-December-20, 11:02, said:

We've tried to fix some of the worst bugs -- it used to double 6NT with 2 cashing aces, then not lead them! (Presumably it envisioned a small chance to get a 2nd undertrick if it didn't set up declarer's kings, and not enough of the simulated hands had 12 tricks available in the side suits.)

This particular problem is harder. It's not so obvious when the results of the simulations need to be ignored. And we can't look at the result at the other table to ensure that it plays the same way, to prevent

And if you think the situation you raised is bad, how about all the times that it leads its singleton trump king, which it probably would have won when declarer takes a finesse? This is a consequence of the use of double dummy simulation -- it "knows" that declarer will play for the drop instead of finessing. I've considered whether we should put in another special case to block this, but there's a reason why it thinks a trump lead is best, and in many cases it doesn't actually give away a trick (if the ace is over the king you were going to pick it up anyway, and if partner has the queen there's no finesse.), and we have to be careful when overruling these decisions.

Everyone who plays robot tourneys learns that things like this happen from time to time; the underlying design that uses DD simulation and statistical analysis has some obvious flaws. Sometimes you're the beneficiary, sometimes you're the victim. If things like this really bother you, you should stay away from GIB.

Our work on improving GIB is primarily focused on fixing problems in the bidding database. We actively welcome reports on these issues.

One of the problem I see with the bidding (at least for me) is the use of law of total tricks when one opens a weak 2 in fourth seat. GIB will raise you even though it may have a very weak hand and opp did not bid.

[mlbridge]

Mlbridge / Hrothgar 17-34

https://webutil.brid...3612&u=mlbridge

[mlbridge]

Mlbridge / Xbabarx 37-28

https://webutil.brid...3641&u=mlbridge

[mlbridge]

Mlbridge / Elyk25 64-22

https://webutil.brid...0069&u=mlbridge

[hrothgar]

mlbridge, on 2018-December-21, 04:19, said:

Mlbridge / Hrothgar 17-34

https://webutil.brid...3612&u=mlbridge

Thanks for a fun match!

[hrothgar]

barmar, on 2018-December-20, 11:02, said:

Our work on improving GIB is primarily focused on fixing problems in the bidding database. We actively welcome reports on these issues.

Here are couple hands from this event that I found annoying

In my world, this is not a raise to 2!S over a double

https://www.bridgeba...C4%7Cpc%7CDQ%7C


I think that GIB needs to cue bid its diamond control

https://www.bridgeba...D4%7Cmc%7C13%7C

[mlbridge]

hrothgar, on 2018-December-21, 04:33, said:

Thanks for a fun match!

Thank you.

It was enjoyable.

[barmar]

hrothgar, on 2018-December-21, 04:40, said:

Here are couple hands from this event that I found annoying

Better to use Robot Report or post them in the GIB forum. I doubt that Georgi is looking here for reports.

Quote

I think that GIB needs to cue bid its diamond control

https://www.bridgeba...D4%7Cmc%7C13%7C

OTOH, maybe you should bid your hearts instead of splintering in clubs, they're a source of tricks. You also could have opened 1♥, planning to reverse in spades twice to show the 6-5 shape.

I've found that GIB is not great at evaluating its hand after splinters, it frequently signs off when there are slam prospects. I'm not sure if we have lots of bidding rules for this, it might rely more on simulations.

Slam bidding is complicated, it's hard to write explicit rules for them, it usually takes judgement.

[cyrenman]

Group B
cyrenman 20 - 44 wackojack

http://webutil.bridg...yrenman&v3b=app

cyrenman 52 - 23 pio_magic

http://webutil.bridg...yrenman&v3b=app

[Mkgnao]

cyrenman-Mkgnao 39-47

https://webutil.brid...273373&u=mkgnao