smerriman

A 4-0 trump break should happen once every 10 hands. Look at the last 100 times you've held 9 trumps, and count how many 4-0 splits there have been. I suspect it will be pretty close to 10, and you're simply imagining things like everyone else who brought this up.

[hv=https://www.bridgebase.com/tools/handviewer.html?sn=human&s=S2HJ87652DQT5C953&wn=Robot&w=SKJ986543HADJ863C&nn=smerriman&n=SQT7HK94D92CT8642&en=Robot&e=SAHQT3DAK74CAKQJ7&d=s&v=n&b=31&a=PPP2C(Strong%20two%20club%20--%2019+%20HCP%3B%2023+%20total%20points%3B%20forcing%20to%202N)P2D(2D%20bid%20waiting%20--%2011-%20HCP%3B%2012-%20total%20points%3B%20forcing%20to%202N)P3C(Opener%27s%20suit%20--%205+%20%21C%3B%2019+%20HCP%3B%2023+%20total%20points%3B%20forcing)P7S(11%20HCP%3B%20strong%20rebiddable%20%21S%3B%2012%20total%20points)DPPP&p=C4C7C9S9S8S7SAS2H3H6HAH9SKSTD7H2SJSQD4H5HKHTH7S5D3D2DAD5HQH8D8H4DKDTD6D9CAC3DJC2CKC5S6C6S3C8CJHJS4CTCQDQ]400|300[/hv]

GIB leads the king because it assumes that declarer will know it is a singleton and drop it under the Ace; therefore it will never take a trick. This of course is silly in reality, but it's just how the robots work. Adjust your sim to assume a 'normal' line of trump play and you'll probably discover that the king costs you the contract many times that double dummy says it makes no difference.

Cyberyeti's suggestion sounds like a good one. Unfortunately, GIB describes 4♥ as only 4+ spades, and won't correct you to 4♠ with this hand. So with GIB, there's no point revealing your double fit; your auction sounds fine.

Despite the description, GIB will still raise with 3 with some 3145 shapes, like most humans.

Here are some examples.

Some double dummy analysis, for reference. (Assumption: North has exactly 6 hearts with at least two of the top three honors, exactly 4 clubs, at most 2 spades, and at most 9 HCP - didn't want to handle odd 6-5 shapes or whether 10 point hands would open 1♥) Both games are makeable 62% of the time Both games are unmakeable 10% of the time Only 4♥ is makeable 12% of the time Only 4♠ is makeable 16% of the time That suggests it is close, but 4♠ is better.

(And also note it doesn't include many tournaments.)

I play with GIB all the time :) It has many bugs, though many people report things as bugs that aren't because they don't know the system (eg your not knowing about constructive raises). Its leads and returns also aren't "bugs", just based on a different style of analysis to humans. So it's more helpful if you can post specific hands to see whether it's actually a bug or not. Not that many get fixed, but that's another matter..

This is not a bug at all; GIB plays constructive raises. And I find GIB is conservative when it comes to opening bids; I've never seen it open an 11 count in first seat that I wouldn't also. As to the others, you'd need to post specific hands. The only unwarranted jumps to 4 I've seen are in some GF auctions when it should be cuebidding (but GIB is terrible at cuebidding) - never when it is too weak (and jumps to 4 are normally meant to be weak.)

In that case I agree with 75%. Whether or not you should bid it depends on how likely you think the other tables are to find a slam. Someone else can check my numbers, but I believe: - in MPs, you should bid grand as long as you expect half of the field to find at least the small slam - in IMPs, non-vulnerable, you only need 9.5% of the field to find at least a small slam - in IMPs, vulnerable, you only need 4.4% of the field to find at least a small slam

The probability really heavily comes down to the hand you have and exactly what the auction was (eg if you asked for keycards I'm not sure how you knew you might be missing the king of spades but no ace, and knowing the point range partner showed and what the missing high cards are impacts the probability he has the king.)

That's true for other suit holdings, but not this one. Cashing an honor, and leading towards an honor, are 100% identical.

But are you going to double? So far the poll have 6 votes for 4♠, 3 votes for pass, and 0 votes for double. If you pass, the first case you mentioned flips - it's better to declare. 4♠ looks like it has chances even with partner holding a minimum, and I'm not prepared to double, so I'm bidding 4♠.

[hv=https://www.bridgebase.com/tools/handviewer.html?s=SAKTHJ73DT95CAT64&d=n&v=n&a=1D2H]200|300[/hv] What do you bid?

You'll need to post the hand. Have never seen GIB pass a jump shift.

As Stephen mentioned, after the auction 1♠ - 4♠, you will often get a good score going down, because if you hadn't bid 4♠, the opponents would have bid and made a higher scoring contract of their own (since 4♠ is weak, the opponents are often quite strong).

Since you have a singleton club, you can bid 4♣, showing heart support and shortness. You can then use Blackwood over opener's response. The other way to game force after Stayman is to bid 3 of the other major. 3♠ is an artificial bid agreeing hearts, and invites a cuebid. You can then use Blackwood over opener's response. Since GIB might well bid 5♣ over 4♣ and not leave you a method to find out about the queen of trumps, I would go with the latter.

Aren't XYZ and FSF 100% identical in this auction? 2♦ is the game forcing bid in both. Edit - I guess they differ in that responder can jump with lots of extra strength/shape, but that's very rare, and even rarer considering we're talking about how to handle opener having extra strength.

https://blog.bridgebase.com/2019/06/19/quiz-when-should-you-use-blackwood/

The article says (emphasis mine): I agree with the OP that this explanation is not a very good one. But I agree with everyone else that 4♦ is the correct bid (just for a different reason; finding the grand.)

What is the upside to Texas then a new suit being exclusion when, as Helene mentioned, Jacoby followed by exactly the same level of bid has no alternative to being exclusion? Is it solely because you're wanting to avoid interference?

[hv=https://www.bridgebase.com/tools/handviewer.html?nn=human&n=SJT5HQ863DT9CT987&en=Robot&e=SA62HAKT97DJ85C65&sn=smerriman&s=SK987HJ52DAQ7CA43&wn=Robot&w=SQ43H4DK6432CKQJ2&d=w&v=e&b=6&a=PP1H(Major%20suit%20opening%20--%205+%20%21H%3B%2011-21%20HCP%3B%2012-22%20total%20points)DR(2-%20%21H%3B%2010-11%20HCP%3B%2012-%20total%20points%3B%20opponents%20cannot%20play%20undoubled%20below%202N)PP1SPPP&p=H4H3HKH2C5CAC2C7SKS3S5SAC6C4CJC8CKC9H7C3CQCTD5H5D6D9DJDQS7SQSTS6D2DTD8D7SJS2S8S4H6HTHJDKS9D3H8H9DAD4HQHA]400|300[/hv] Not only did the opponents let me play in 1♠ undoubled, they were kind enough to let me make it.

I agree(d).

Auto-splinters are part of Bridge World Standard, so I'm not sure I'd call them irrational. I'm with johnu, they're one of the best ways to get information out of opener, given you already have keycard, a general slam try with transfer then 4M, and cuebids after Texas.