Kaplan Inversion ( Interchange )

[jerome keslin]

[jerome keslin]

Kaplan inversion.

Does anyone play this?

This hand was given for opener.    I have supplied a hand for responder.

xxxx      Axxx

xxxxx    xx

AQ        xxxx

AK        Qxxx

1. After, opening 1nt that becomes  the final contract.

2. After opening  1 heart, and getting a forcing nt response, maybe its best to pass?

3. Playing Kaplan inversion, responder bids 1s ( 0-4 spades ), opener rebids 1nt to show 4s, and 2s is the final contract.

---------- Forwarded message ---------
From: jerome keslin <jet...@gmail.com>
Date: Sun, Nov 22, 2020 at 11:40 AM
Subject: Kaplan Inversion ( Interchange )
To: <kaplan-s...@googlegroups.com>

[Christopher Monsour]

OK, yes, in some partnerships I have played Kaplan Interchange, but not in my KS partnerships.

I even wrote an article for The Bridge World about 6 years ago called "Interchange Improvement" with a multi-purpose 2C rebid (including hands that would typically rebid 2D, 2H, 3C, or 2-1/2 H) after 1H-1S that allows a 1N rebid with a balanced hand, a 2D rebid with clubs, and a 2H rebid with spades but not enough strength for 2S.  Using that system, I'd bid these hands 1H-1S-2H-2S.  Note that all balanced ranges by opener are biddable here: 1H-1S-1N can be 12-16 and use an artificial range-find, allowing 1H-1S-2N to be 17-18 and 1H-1S-3N to be 19.

I came up with this because of a (strong NT) partner who insisted on playing Interchange *and* having a 1H-1S-1N be natural, and I was fine with that but was not about to waste the 2D opening on Flannery.

Unfortunately, I feel Interchange works better with a strong NT.  The reason is the 1N response showing 5+ spades.  Then after 1H-1N, one can rebid 2S with 2533 and 12-14 and 2N with 2533 and 18-19.  The 2533 15-17 hands are quite awkward.  I don't like just rebidding three-card minors.  However, you could certainly work out a structure where 2C shows diamonds or strong NT 2533 and 2D shows clubs, similar to what I worked out in my BW article.   But none of my KS partners ever wanted to play Interchange.  

If you are NOT playing Interchange I strongly recommend using a combination of range-find and checkback after 1H-1S-1N to allow a 12-16 range.  I've tried to get that published in Bridge World also, but Rubens is so convinced there's no way to make a 12-16 1NT rebid playable that he rejected the proposed article seemingly without reading it.

Chris Monsour

---

From: kaplan-s...@googlegroups.com <kaplan-s...@googlegroups.com> on behalf of jerome keslin <jet...@gmail.com>
Sent: Sunday, November 22, 2020 3:51 AM
To: kaplan-s...@googlegroups.com <kaplan-s...@googlegroups.com>
Subject: Fwd: Kaplan Inversion ( Interchange )

 

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[Alex Martelli]

On Sun, Nov 22, 2020, at 4:15 AM, Christopher Monsour <cmon...@msn.com> wrote:

OK, yes, in some partnerships I have played Kaplan Interchange, but not in my KS partnerships.

I even wrote an article for The Bridge World about 6 years ago called "Interchange Improvement" with a multi-purpose 2C rebid (including hands that would typically rebid 2D, 2H, 3C, or 2-1/2 H) after 1H-1S that allows a 1N rebid with a balanced hand, a 2D rebid with clubs, and a 2H rebid with spades but not enough strength for 2S.  Using that system, I'd bid these hands 1H-1S-2H-2S.  Note that all balanced ranges by opener are biddable here: 1H-1S-1N can be 12-16 and use an artificial range-find, allowing 1H-1S-2N to be 17-18 and 1H-1S-3N to be 19.

I came up with this because of a (strong NT) partner who insisted on playing Interchange *and* having a 1H-1S-1N be natural, and I was fine with that but was not about to waste the 2D opening on Flannery.

Unfortunately, I feel Interchange works better with a strong NT.  The reason is the 1N response showing 5+ spades.  Then after 1H-1N, one can rebid 2S with 2533 and 12-14 and 2N with 2533 and 18-19.  The 2533 15-17 hands are quite awkward.  I don't like just rebidding three-card minors.  However, you could certainly work out a structure where 2C shows diamonds or strong NT 2533 and 2D shows clubs, similar to what I worked out in my BW article.   But none of my KS partners ever wanted to play Interchange.  

If you are NOT playing Interchange I strongly recommend using a combination of range-find and checkback after 1H-1S-1N to allow a 12-16 range.  I've tried to get that published in Bridge World also, but Rubens is so convinced there's no way to make a 12-16 1NT rebid playable that he rejected the proposed article seemingly without reading it.

Heh -- I'm struggling (on paper only) with Ron Feldman's new "Card Pro" bidding system (maybe a reason I don't get it, with all the weird capitalization, italics &c, is hidden in Amazon's age rating for it of "Age Level: 12 - 18" -- my oldest grandson is nearing 12, so I'm a couple of generations behind... funny because Ron's older than me!-). There, a 1NT opening bid is 12-16 -- the book claims 13-15, but it has no other way to open with 12 points balanced hands, and the alternative with 16 (better be pretty good ones!-) is 2 clubs, showing 16+ to 20 balanced... and of course ruling out the possibility of playing 1NT!

With all balanced hands pushed away from one-of-a-suit opening bids, the 1-suit openers become magical -- even one club can guarantee a 5-card suit or a 4-card suit with some 4441, making competitive sequences super-turbo-boosted. Plus, opener's rebids of 1N and 2N can be arrayed as for some Gazilli-like conventions (the system does use 2C Gazilli-ish after 1M-1N, though it doesn't call it that -- indeed to improve the latter, it opens 2M as Roman, 5M+side clubs!-) -- whether Feldman's treatment of these sequences is optimal (and/or rememberable:-) is secondary, it's the concept of never opening any balanced hand 1 of a suit (potentially with exceptions for superstrong 5-carder with 5332, but those don't rebid in NT) that I find revolutionary in Ron's system.

However, the price you pay for that is -- inferior (too-loose-range) constructive bidding with any balanced opener (also, 2D instead of 2C for game-forcing hands, but that's a price French Standard has chosen to pay for a very long time since they use 2C for strong but not-game-forcing hands, and, like their Benjamin precursors, they seem to be doing fine with the tradeoff -- after all, super-strong hands are quite rare, though momentous when they do happen). But - the super-high-frequency balanced hands are what I'm trying to wrap my mind around, hard to do in pure theory (can't find anybody willing to try out the system with me!-).

If 12-16 1NT rebids are just too wide to handle (didn't Flint-Pender use to do fine with those a long, long time ago?), then what about 12-16 1NT opening bids?!

Alex

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[Adam Wildavsky]

Mark Feldman and I are experimenting with layering Mats Nilsland's "Scanian" system on top of a 12-14 1NT. Balanced hands of 18-19 or 22+ are opened 2♣. This has worked well enough for us so far, but we've only been playing it for a month or so.

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[judyorcarl]

12-16 1NT is OK PROVIDED

the 12's have 3 10's and the 16's have no aces.

But that doesn't help with other 3-QT hands or the great preponderance of 16's