[uva72uva72]

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IMPs, ACBL robot individual

Is there no chance of getting the range for the robot's "retreat" from no trump lowered to something like 6-9 so that it doesn't include hands as strong as that North holds in this instance? Note that those who chose to rebid 1♠ rather than 1NT heard North bid 3♦ (invitational, 10-12) with the same hand. Yet, if anything, the 1NT rebid should be more encouraging to North, since it guarantees at least 2♦. That is one of the reasons I prefer to rebid 1NT, rather than 1♠, along with the likelihood that no trump may be the safest/easiest game if partner has long ♦. In fact, the bidding structure is specifically set up to allow a 1M response with 4 cards only followed by a "drop dead" jump to the 3 level in the other minor over a 1NT rebid. If North and South take advantage of this structure, then there is no need to worry about missing a major suit fit. If North has 4M with 5/6♦ and a weakish hand, it can bid 1M first. If it has a game-going hand, it can bid 1♦ then reverse into the major suit to show its strength. South can rebid 1NT knowing that if North has a 4-card major North is also strong enough to bid it on the way to game.

Recently I experienced an auction in which North opened 1♣, rebid 1♠ over my 1♦, bid 3♣ over my 2♥ and bid 3♥ over my 3♦. From North's studious avoidance of NT and ♦, I concluded that its hand was something like 4-3-1-5 or 4-3-0-6 with no heart honor. In fact, North was 4-3-2-4. Over an original 1NT rebid by North, I have an easy raise to 3NT, knowing that partner has at least 2♦ so that my suit can be established and run.

Note that among those playing the display hand was a BBO-savvy player who "retreated" to 2NT from North's 2♦ "retreat". That's a very astute action, and it may be what it takes to win, but is it bridge?

[1eyedjack]

As well as promising 2-3 Diamonds, the 1N rebid denies 4 Spades. Having only xx in Spades and maybe an expectation of a Spade attack from the defence, this might account for its reticence. I only speculate.

Furthermore, I do not think that a 1S rebid is limited to 14 HCP. GIB may worry that with a bit extra South may pass a simple 2D rebid. Again I speculate.

Personally I agree with you.

[lycier]

why not jump bid 3♦ for invitation after rebid-1nt?

[uva72uva72]

I don't think the issue is hand-specific. The robot consistently "retreats" from no trump with 10-11 HCP when it should be passing 1NT or even inviting with 2NT (or, in this key, jump rebidding its suit). Sometimes, for example, it jumps to 3 of the other minor (I believe it's called a "drop bid") with 11 HCP and a holding of Jxxxx. So, instead of being +150 or +600 you end up -100 with a combined 24-25 HCP because your holding in the other minor was Ax and the suit didn't split 3-3.

[Bbradley62]

It has been suggested several times that the word "retreat" in the description is misleading, and suggests fear or scrambling, not constructive bidding. Removing the gratuitous "retreat from NT" label would be a simple way to make at least a little progress.

[Stephen Tu]

I don't care whether they call it retreat or not, just fix the range to be something more reasonable. 6-10 TP is fine IMO. IMO I'd evaluate the hand as 12 total points and clear invite, they need to tweak its evaluation of good long suits and not just count 1 pt for doubleton.

And the so called "bar bid" of 1c-1s-1nt-3d etc. should be fixed to be 4-6, not random 4-5s.

[lycier]

Another example:

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[Bbradley62]

This one (posted by Lycier) is not so clear. GIB presumes that West's 1N denies 6♥ or 4 of anything else. So, diamonds rate to be a problem in NT (EW combined maximum of 4 cards in that suit) and West has some chance of having 3 spades. I think 2♠ is reasonable over 1NT.

[Bbradley62]

Another one of these... Why exactly is North retreating from NT?

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