Splinter response

[mgoetze]

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How much better does GIB want its hand to be to give me a diamond cuebid?

[georgi]

Currently for GIB the 4♣/♦ here won't be a cuebid. 4♦ means - Help-suit slam try -- 3+ ♦; 3+ ♥; 2-11 8421 HCP in ♦; 9-10 total points

 

So likely it needs some change toward cuebids.

[mgoetze]

Ah yes - personally I think there are way too many of these HSSTs littered around the system.

 

Nevertheless, I note that GIB N does have 9 total points, 3+ ♦ and 5 8421-points in ♦.

[xxhong]

Help suit slam try is a big nonsense. No any good players in this world play this convention and it is simply bad because slam is a matter of accurate science in constructive auctions.

 

Currently for GIB the 4♣/♦ here won't be a cuebid. 4♦ means - Help-suit slam try -- 3+ ♦; 3+ ♥; 2-11 8421 HCP in ♦; 9-10 total points

 

So likely it needs some change toward cuebids.

[cloa513]

Or else GIB should jump to 5♥ and you should judge that it has a max of working points without a cue bid.

[barmar]

The problem is that GIB doesn't know Italian-style cue bidding. It always bids first-round controls first. Since these aren't so common, it uses these HSSTs instead.

 

As for why it didn't look for slam on this hand, I don't think we have much in the way of explicit rules for how to bid after partner splinters, instead we depend on simulations to tell it how useful it is. In this case, the simulations told it that slam was unlikely. Here's the count of different spade suits it dealt you, on the 143 hands it dealt in my testing:

 

55 A

28 x

24 K

18 Q

14 ---

4 T

 

I'm not sure why it dealt you singleton honors so much (maybe just because it was giving you lots of honors in general, so there's a good chance your singleton is one of them), but they're wasted.

 

And even with a low singleton, slam is still unlikely. For instance, take one of your little clubs and make it a spade, and now you have two losers, not to mention needing the club finesse. So even 5♥ is not a very safe contract opposite most of your likely hands.

 

What makes your hand so great in this case is that you have a spade VOID, but GIB only dealt you that 10% of the time (and the slam is still on the club hook). Unfortunately, cue bidding 4♠ doesn't help -- GIB thinks that shows the A, not a void -- it's the old problem that GIB's bidding rules don't have a way of showing "A or B", so it can't show "Ace or void". And while a singleton A is nice (you don't have any losers in the suit), the problem is that it takes away from honors in other suits, so you're likely to have club or diamond losers.

[mgoetze]

The thing is that after 1♥-2♥, a splinter is supposed to say, "Partner, I know you don't have much, but if you don't have wastage in spades a slam might well be on anyway." If GIB is not dealing me such hands, then there is something wrong with the definition of the 3♠ bid. Perhaps the definition of the splinter should include something like "1- 8421 HCP in S".

[barmar]

The thing is that after 1♥-2♥, a splinter is supposed to say, "Partner, I know you don't have much, but if you don't have wastage in spades a slam might well be on anyway." If GIB is not dealing me such hands, then there is something wrong with the definition of the 3♠ bid. Perhaps the definition of the splinter should include something like "1- 8421 HCP in S".

I don't think it would make much difference.

 

A splinter is much more likely to be a singleton than a void. And it has 3 small clubs -- what's the chance that you can cover all of them? And if you can, then are you also likely to have the ♦A? You happen to have a perfecto because your splinter was a void, and it still needs something good to happen in ♣ for slam to make.

 

Here's a hand where the robot is more likely to go looking for slam when you splinter: xxx KT9x KJT Qxx. That filler in clubs is important.