georgi

And if 2♥ Doubler person has one suiter 17+HCP ? What he should do over 4♠. Calm pass? Is new suit ( say 5♣, now cuebid slam-try or natural explanatory hand call ). A slam could be still at the table with singleton ♥A. 4♠ would very likely be passed out. Apparently responsive double wasn't supposed to be final contract and with lack of common call 4♥ could follow with balanced hand and 4♠ would be still reached.

In theory you're right, but the is slim chance you could be missing the stopper in unbid major. So 2NT could be a minimum ( 12-13 ) or maximum ( 14 ) with no stopper in it.

Currently there is no lower limit. Hand like: 23.234.23.234567 would step for 2NT transfer. Would be addressed for consideration as 2S is already used for minor stayman, so responder has no way to negotiate with opener about possible/impossible 3NT based on his opening values and support in minor.

At the moment GIB uses Responsive double only with 2- cards in partner's suit. Obviously when both suits shown from partner and opponents are minors Responsive double would be profitable to be 3- and 4-4 Majors to pop-up.

Thanks for reporting. It will be addressed for improvement from responder's side as GIB might need more followns there. At first place here cuebid 2♠ ( or any suit they've shown ) would be fixed so GIB could easily force to game and later to give fit.

Thanks for reporting. Fixed in v31. Cue here for GIB was intended to show lack of fit 2- cards and much stronger hand. Explanation used to show this wrongly. Also GIB would now bid 4♥ with that hand.

[hv=http://www.bridgebase.com/tools/handviewer.html?bbo=y&lin=pn|42krunner,~~M33494,~~M33492,~~M33493|st||md|4SJQH6KD68JQKC468K%2CS39KH23489QD4C39J%2CS478AH7D2379C27TA%2C|rh||ah|Board%2010|sv|b|mb|p|mb|1N|mb|p|mb|2C|an|Stayman%20--%20%20%20|mb|p|mb|2D|mb|p|mb|p|mb|p|pc|H4|pc|H7|pc|HA|pc|H6|pc|S2|pc|SQ|pc|SK|pc|SA|pc|D2|pc|D5|pc|DJ|pc|D4|pc|DQ|pc|H2|pc|D3|pc|DA|pc|S5|pc|SJ|pc|S3|pc|S4|pc|DK|pc|H8|pc|D7|pc|DT|pc|HK|pc|H9|pc|C2|pc|HJ|pc|C4|pc|C3|pc|CA|pc|C5|pc|CT|pc|CQ|pc|CK|pc|CJ|pc|C6|pc|C9|pc|C7|pc|ST|pc|S9|pc|S7|pc|S6|pc|D8|mc|10|]399|300[/hv] To initiate Stayman with garbage hand GIB needs 4450 shape. Here default rebid for GIB is 2NT instead of pass, but simulation showed somehow that pass is also an option.

When there are some undefined calls and blurred situations new suit is explained like 4+ cards and some amount of TP more or less. like here 4+ spades and 20-TP. That makes GIB sitting in front hesitating to stay or move to better place ( from its point of view ). I am not justifying 3♣, but trying to provide information about why and when GIB does it. Hence these situations are altered so GIB would be at least aware of what human would consider them, even if not pick by itself. As Gerber convention in example. By showing appropriate and expected length of such intervene GIB as partner would believe there is no reason to move.

Let say GIB had 8753/753 The lead would be 3. Not 7. So by seeing 7 and then 8, GIB-East knows 7 is from ( 7/73/75 ). 8753 is off by default as declarer cannot be singleton. 753 is not possible and neither Q75/Q73/Q87 which makes declarer not having just 8(5/3). So with impossibility of Qx in declarer's hand, diamond continuation doesn't need to be in rush. It will cash declarer's Q as additional trick while heart stopper, if just one, is not kicked out. GIB is not considering 8 to be misleading or random. It just deals declarer with some cards and no matter what declarer throws away. It's not GIB-East problem. 8 is as important card just to help defender confirming the partner's or declarer's holding in some suit.

The invite will say now: Invitational to 3NT game -- 3-5 !C; 3-5 !D; 3-4 !H; 2- !S; 17-18 HCP As supposedly with 19HCP GIB would rather just bid game. East would still bid 3NT over such invite with current hand.

Fix was that once there is GF settled by 2M here, GIB with no stopper in 4th unbid suit has to just bid their minor suit. 2NT would show the stopper in unbid suit, 3 minor is just like default rebid when no stopper.

3♣ shows loaded hand although it's not just because South showed 4+♠ and 0+ TP. 3♦ raise would need 10-12TP, so 2TP short. On the other hand East could also bid 2♥ ( 6-9 TP) , but 4-4 looked better than 5-2. After simulating it could find it, although not so often.

After 3NT opening GIB plays: 4♣ - Gerber 4♦/4♥ - Major transfer. 4♠ not defined 4NT - Quantitative 6-7HCP. 5♣/5♦ - 6+ cards naturally, 4-6TP.

With Q8753 and NT contract, supposedly not some clues, like 1N P P P, GIB would lead 5.

V31 would have it similar to direct overcall meaning ( showing better spades, as biddable is 4+ ), just little reduced and limited as top range. 20TP seems too many to be passed initially. GIB would double with 18/19+TP or just bid 2M. Showing this, partner won't be so frisky to move out.

That would be improved in v31. So when 1NT person is bidding own suit in similar auction ( partner is silent ) it will say 5cards and not 5-. Also aside suits would be reduced to some balanced length instead of 2-5 elsewhere. I.e. 3♣ here would show : -- 5 ♣; 2-3 ♦; 2-4 ♥; 2-4 ♠; 17 HCP; 18- total points

Thanks for reporting. Fixed in v31.

GIB as South would bid the same you did, 3♦. For GIB they are identical and GIB picks the first available. 3♠ would come in use if North continued with 3♦ instead, so 3♠ would be the only one left to show support in minor. Back to club suit forcing if South has used 3♠, GIB North would just bid 3NT. That of course doesn't justify the freak-out 4♥. Book bid is Pass, so GIB moved after second thoughts. V31 contains a fix about this move out. GIB won't consider any longer 4M run away. The only possible chance if 5m, but it might happen based on some tests in just 5% of cases. So 95% Pass/5% 5m. Currently in v30, GIB used to run away in about 40% of hands to 4M.

2NT shows -> -- 2-5 ♣; 3-5 ♦; 2-4 ♥; 2-4 ♠; 11-14 HCP; 12+ total points; partial stop in ♣; partial stop in ♥; partial stop in ♠

Thanks for reporting. It's fixed in v31. I think there were previous post about similar issues caused by this bug. The bug caused GIB to rebid 4♣ automatically with any 4ths. However, now would bid 4♠ on 3♥.

From human's point of view it's easy to set this slam down immediately. But for GIB this passed hand, having 18HCP where it could be unlikely 12 and more likely 11HCP as maximum, leans that partner is normally to have 6-7HCP instead of 0. So GIB is trying to make best result, -1 seems the least EW could take. GIB's strength is not to reveal psych calls. Sometimes these contracts would be lucky.

Thanks for reporting. Pass is fixed in v31.

Thanks for reporting. GIB wasn't intended to pass, has to bid 3NT, but after second thought ( simming ) its picked to pass. Fixed this in v31.

Thanks for reporting. Fixed in v31. The GIB's idea was re-transfer. just crossed with slam rules explanations. Real meaning is now : !Retransfer -- 5+ !H

3♦ and 3♠ ( the unbid suits ) have same meaning. they both showing 2M cards and 4-5 in minor. Would be investigated about that 4♥ leap up. Along the way also for 3minor GF call.