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IMprecision 2C

#1 User is offline   straube 

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Posted 2017-November-17, 10:56

An advantage of this structure are finding 4-4 major suit fits when responder has only GI values. I titled this IMprecision 2C but it could be used for Precision 2C openings that similarly promise 6 clubs and deny a 5-cd side suit.

2D-GI 5+S or any GF
.....2H-4D, 4H or 1-suited low short
..........2S-GF relay
...............2N-4D
...............3C-4H
...............etc-1-suited lower short
..........2N-5+S/4H
..........3C-5S
..........3D-5S/5D
..........3H-5S/5H
.....2S-bal lower fragment or 1-suited high short
..........2N-GF relay
..........3C-5S
..........3D-5S/5H
..........3S-6S/4H
.....2N-1-suited mid short
..........3C-GF relay
..........3D-5S/5D
..........3S-5S
.....3C-3226/2227
..........3D-GF relay
..........3H-5S/5H
..........3S-5S
.....3D-4S, higher short
.....3H-4216
.....3S-4306
.....3N-4207
.....4C-4117, 6-7
.....etc

2H-GI+, 4+H
.....2S-4S, f
..........2N-5H, f
.....2N-3H, f
.....3C-0-3S, 0-2H, nf
.....etc-max, stopper asks

2S-constructive+ without a major
.....2N-counter-try
.....3C-minimum
.....etc-maximum, stopper asks

2N-GI+, 4S

3C-bump

3D-GI

3M-GI, tends to deny OM
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#2 User is offline   awm 

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Posted 2017-November-17, 11:33

IMPrecision already finds 4-4 major fits on invitational hands. Again our method is:

2 - 2 = INV+ relay
... 2 = one-suited
... 2 = 4
... 2N = 4
... 3 = 4 and MIN
... 3+ = 4 and MAX

So we are ahead when opener has 4 and max (we know it's a max, and otherwise are in the same place), same place when opener has hearts (because 3 is the relay there, as we need 3 NF), and ahead when opener has diamonds. We probably break even when opener has spades and min (we're a step behind you, but we know it's a min). You're ahead on relaying out the one-suiters, but in exchange you are forced to open 1NT on all max semi-balanced hands (because you bid 2 on INV hands and the 3 rebid by opener cannot distinguish max/min). You're also less efficient when responder has 5+ INV (since your 2 response could be four hearts only). And you're losing the 3-new-suit bids to show INV hands (although I'm not sure you can't put one-suited major invites through 2/2?)
Adam W. Meyerson
a.k.a. Appeal Without Merit
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#3 User is offline   straube 

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Posted 2017-November-17, 12:14

I'd still open bal max 2C, not 1N. The idea is that after 2C-2D, 3C I'll break relay with 5S. So half the time we'll be in a 5-3 fit and the other half regrettably a 5-2 fit.

Sorry for not remembering IMprecision could pick up 4/4 major suit fits. This loses 4-4 diamond fits as you say, but I find 4/4 heart fits with 5S/4H invitational opposite minimum 4H/6C. I don't think the current structure does that.

I still pick up 5/3 heart fits. It goes 2C-2H, 2S-2N or 2C-2H, 2N but it does take longer.

I like having 2C-3M as GI as it has less chance of losing 6-2 major suit fits.

So this is ahead on unbalanced single-suiters and handles 5S/4H GI, loses 4/4 diamonds (but not 5/4 fits), plays 5-2 spade fits when opener is min 2227. Fair summary? Not sure if this does better with 5S/5D hands. Probably not.

Does it add some clarity, however, for 2C-2S auctions? Now we know we're looking for min/max and stoppers. It can also look for stoppers after say 2C-2N (showing exactly 4S) as 3D and 3H show interest in 3N and weakness in these suits.
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#4 User is offline   foobar 

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Posted 2017-November-17, 19:17

View Poststraube, on 2017-November-17, 12:14, said:

I'd still open bal max 2C, not 1N. The idea is that after 2C-2D, 3C I'll break relay with 5S. So half the time we'll be in a 5-3 fit and the other half regrettably a 5-2 fit.

Sorry for not remembering IMprecision could pick up 4/4 major suit fits. This loses 4-4 diamond fits as you say, but I find 4/4 heart fits with 5S/4H invitational opposite minimum 4H/6C. I don't think the current structure does that.

I still pick up 5/3 heart fits. It goes 2C-2H, 2S-2N or 2C-2H, 2N but it does take longer.

I like having 2C-3M as GI as it has less chance of losing 6-2 major suit fits.

So this is ahead on unbalanced single-suiters and handles 5S/4H GI, loses 4/4 diamonds (but not 5/4 fits), plays 5-2 spade fits when opener is min 2227. Fair summary? Not sure if this does better with 5S/5D hands. Probably not.

Does it add some clarity, however, for 2C-2S auctions? Now we know we're looking for min/max and stoppers. It can also look for stoppers after say 2C-2N (showing exactly 4S) as 3D and 3H show interest in 3N and weakness in these suits.


Couple of comments:

1) One of the really nice things about the IMP 2 - 2 relay is the sheer mnemonic elegance. Basically, one simply bids 4-card suits up the line, and it's more or less symmetric after that, with the extra values and 4 being the icing on the cake.

2) This structure seems symmetric to 2, which may ease the above concern a little bit, but it seems like there are still some oddities like clubbing the low shortness first with the "other suits" (instead of the standard scheme of high to low)
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#5 User is offline   straube 

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Posted 2017-November-18, 06:07

I agree that the present IMprecision structure is very easy on the memory. I'm just trying to apply a technique Adam and Sieong have used for their 1M
openings to their 2m openings. Eliminating the need to show GI in a major created huge savings elsewhere.

So I rewrote a structure to address concerns about the 7222 vs GI 5S and also the loss of a 4-4 diamond fit. Unfortunately I don't think it can be identical to the 2D structure. But I did use Atul's high to low suggestion. The fortunate thing about 2C is that there is so much room.

Anything not to like about this?


2D-GI 5S or any GF
.....2H-4D or high short or bal
..........2S-GF relay
...............2N-4D
...............3C-high short
...............etc-bal
..........2N-4D
...............3C-min
...............3D-fit
..........3C-5S
..........3D-5S/5D
..........3H-5S/5H
..........3S-6S/4H
.....2S-4H
..........2N-GF relay
..........3C-5S
..........3D-5S/5D, rare
..........3H-5S/4H
.....2N-mid short
..........3C-GF relay
..........3D-5S/5D
..........3S-5S
.....3C-low short
..........3D-GF relay
..........3H-5S/5H
..........3S-5S
.....3D-4S, high short
.....3H-4216
.....3S-4306
.....3N-4207
.....etc-4117
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#6 User is offline   foobar 

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Posted 2017-November-21, 11:00

Aren't almost all existing responses to 2D, already tailor made for the stated design goal of repurposing it as GF or 5+ spades with 12+? I suppose you can be in a little bit of a pickle with a min hand with short clubs over 2S/2N, but that's a specific case, and the chances are that you'll have some other rebid. IMO, it seems best to leave 2D "as is" and see if the new semantics offer improvements over 2H/2S.
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#7 User is offline   straube 

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Posted 2017-November-21, 11:10

Yes to your question. I don't understand the rest of what you're talking about.
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Posted 2017-November-21, 11:16

What I meant is that you don't really need to change 2D responses, but there might be merit to see if the new semantics (which free up the traditional meaning of 2S), lead to better auctions.
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Posted 2017-November-21, 13:51

I understand now. How am I in a pickle after 2C-2D, 2S/2N? If a 2S rebid (showing 4H) I just retreat to the anchor suit (3C) if I have 5S but not 4H. If a 2N rebid, opener will have 3 spades when 3136,3127,or 3037 and at least 2 spades with 2137 so I rebid 3S. If I happen to also have 5D, I can offer a choice of spades or diamonds.
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Posted 2017-November-21, 15:20

View Poststraube, on 2017-November-21, 13:51, said:

I understand now. How am I in a pickle after 2C-2D, 2S/2N? If a 2S rebid (showing 4H) I just retreat to the anchor suit (3C) if I have 5S but not 4H. If a 2N rebid, opener will have 3 spades when 3136,3127,or 3037 and at least 2 spades with 2137 so I rebid 3S. If I happen to also have 5D, I can offer a choice of spades or diamonds.

Sure -- by pickle, I meant really awkward invitational hands with say 5=3=4=1 or similar that have to retreat to 3 over 2...2...2. In IMP, the bidding might have gone 2...2, giving an opportunity for opener to rebid 2N (presumably NF with misfit).

Granted, it's debatable whether 2N plays any better than 3C with such a hand, and these corner cases likely aren't worth too much thought.
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#11 User is offline   straube 

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Posted 2017-November-21, 15:33

I thought he might have used that for showing hearts.
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