smerriman

[hv=http://www.bridgebase.com/tools/handviewer.html?sn=smerriman&s=SK2HAJ954DKT3C987&wn=Robot&w=S8HKQT3DJ98CKQT32&nn=Robot&n=SQJT975H2DQ74CA54&en=Robot&e=SA643H876DA652CJ6&d=w&v=b&b=4&a=P2S(Weak%20two%20bid%20--%201-4%20%21C%3B%201-3%20%21D%3B%201-3%20%21H%3B%206+%20%21S%3B%206-10%20HCP%3B%207+%20total%20points)PPD(3+%20%21C%3B%203+%20%21D%3B%204+%20%21H%3B%2011-%20HCP%3B%2012%20total%20points)P2N!(Lebensohl%20-%20Forces%203C%20by%20partner%20--%209-%20total%20points)PPP&p=SKS8S5S6S2H3S9S4SQS3C7C2SJSAC8D8CJC9C3CASTD2H4HTS7H8D3D9DQD6DTDJD4DADKHQC6H5CKC5CQC4H6H9CTH2D5HJHKD7H7HA]400|300[/hv] Basic robots. Not sure how they could go wrong here. edit - East definitely intended 2NT as lebensohl, rather than natural (bids 2NT with a yarborough).

Actually, 3♠ doesn't show 5 spades; it shows: 2-5 ♣, 4-5 ♦, 2 ♥, 2-5 ♠, 15-17 HCP So it seems GIB is treating it as 4 card diamond support, which is why it is then trying to get to 6♦. It seems it doesn't have a way of finding a 5-3 spade fit in this sequence.

Happens all the time sadly :( A similar idea applies to GIB declarers who have a 100% line, and a line which works if the bidding can be 100% trusted, and it takes the latter and goes down, rather than assigning tiny probabilities to exceptions and breaking ties that way. These types of things have been mentioned so many times, it's clear that BBO aren't capable of fixing them.

And the description of 4♠ showed 1 or less spades, so why would you pass?

With the deadline approaching there are a lot of players well behind schedule. If your opponents aren't responding, post here so we know who is at fault if they don't complete before the deadline. For reference, I challenged mkgnao early on but it was rejected, so I sent a PM saying to challenge me when ready - got a response saying thanks, but still awaiting the challenge.

Odd indeed - it bids 2♠ without the 2♥ bid, so it's not just a HCP/TP thing, but also bids 2♠ over 2♥ if you add 1 extra point anywhere. So does look like some sort of 'off by 1' issue to do with points when south interferes.

5.5 - 4.5 to icycookie looks correct to me, though obviously since MP requires a completely different strategy, it's probably best to replay it (unless you both agreed to play it as MP).

Yep, I discovered that a while back as well, plus a significant number of other exceptions. (Never followed that up with a full no trump listing, since I couldn't really come up with any rules regarding leads from multiple honors)

Surely the only time GIB would vary its tempo is when it's running a simulation vs not running a simulation, which is nothing to do with the hand it has, just based the auction prior to that. Anything else will just be due to lag (and confirmation bias :P).

"based on double dummy analysis", so no. But what wbartley says is true; if you force the defense to lead their longest/strongest suit, the probability of 3NT rises to about 60%, which is probably more than it'd go down based on the Kx duck.

smerriman 5.5 - 4.5 wackojack http://webutil.bridgebase.com/v2/tview.php?t=ARDCHALLENGE:334f55c8.dc6b.11e7.a200.0cc47a39aeb4-1512773863&u=smerriman

A quick sim of 500 hands showed 3NT making 50.8% of the time based on double dummy analysis. But since we're comparing to 3♣ (which makes 92.6% of the time), rather than a partscore in no trumps, it's a lot closer than it sounds. Looks like 3NT comes out on top, but not by more than 1 IMP.

smerriman 6 - 4 hanoi5 http://webutil.bridgebase.com/v2/tview.php?t=ARDCHALLENGE:98d5426d.dc59.11e7.a200.0cc47a39aeb4-1512766303&u=smerriman

PS - early days yet but I'm not sure if 0nsfvalue is actually playing; he never signed up in the original thread (just asked what the schedule would be).

smerriman 6 - gszes 4 http://webutil.bridgebase.com/v2/tview.php?t=ARDCHALLENGE:a298f1b6.db84.11e7.a200.0cc47a39aeb4-1512674836&u=smerriman

I'd disagree - it's highly unlikely opener has 4 diamonds (would need to hold a minimum 2344 or 3244 and not have rebid 1nt). And it's not just a choice between the two fits, since bidding 2♦ can get you to game whenever opener bids on, which will heavily skew the results towards bidding.

smerriman 7 : 3 42krunner http://webutil.bridgebase.com/v2/tview.php?t=ARDCHALLENGE:5463d63b.dae0.11e7.a200.0cc47a39aeb4-1512604268&u=smerriman

So you disagree with the description of 3♦. If that is changed, the double won't happen. The logic that led to the double is not the issue.

Maybe I'm missing something. With partner holding a known singleton or less in hearts, aren't you going to get a heart, a diamond, a heart ruff, and a diamond ruff at the very minimum? Unless there's a 5-1 heart split, and even then partner still has to have several more high cards to make up the 10 points..

Exactly.. so West can't have 4 spades like you said, or there would be at least 15 spades in the deck.

No, GIB is not doubling on HCP, it's doubling on a simulation. It doesn't matter whether you think 3♦ should mean something else - you have full knowledge of what GIB will take it to mean when you made it; if you get punished for misleading your partner that's your own fault. No idea what you mean about West having 4 spades; that's impossible since the opposition have shown 4-4. It's almost impossible to find a West hand matching the bidding that doesn't set 4♠, so the code that ran the simulation was correct. It doesn't need a 'new simulation program'.

I think it would be best to keep this forum concentrated on regularly occurring, clear-cut bidding sequence bugs, not a multitude of highly competitive auctions like this. I suspect it's more likely to put off the developers from reading through all the threads to find more fixable bugs than achieve anything else. Once again, a human (West) has made a bid that is completely inaccurate based on GIB's system. Can you think of many hands where West does have 1- heart, 10+ total points, passed initially, and 4 spades makes?

GIB describes it as 12+ total points regardless of vulnerability or position. (Thus the reason the description for the above auction is exactly 12 points - at least 12 for the bid, and at most 12 for not opening, and the most likely reason for apparent strangeness after that). So that's what would need changing, and then the double would most likely not occur.

I think steve2005 means you should be able to bid 2NT with a weak hand. That may be true, but not how GIB plays it.

On the other hand, maybe it does make sense (the logic, rather than being a good bid, obviously). There are only a tiny range of hands where you can have the described 12 total points yet not open the bidding - perhaps enough of these allow you to take quick tricks and/or ruffs.