[arrows]

When and only when your partner opens 1♥,
interchange the meaning of 1♠ response and 1NT response.

I saw some players using it in tournement. and I heard it is called
Kaplan switcheroo, not sure if I get it right, I tried to google it, but
nothing found. I'd be grateful if some one can help to explain the
implication of using this convention, pros and cons,
etc. or anything about it.

[hrothgar]

try "Kaplan Interchange"

[mikestar]

Also known as Kaplan Inversion, and in England as Granville (after a player who independently invented it, no doubt).

The basic advantage is that it simplifies the handling of Flannery-type hands (4 sapdes-5 hearts, insufficient values for a reverse.)

For those of us who have to play in the ABCL, it is not General Convention Chart legal (though it was for a while).

There are two flavors of KI. In both, 1S substitutes for 1N forcing and 1N shows spades.

In the first method, 1N shows 4+ spades and 1S shows 0-3 spades.

In the second method, 1N shows 5+ spades and 1S shows 0-4 spades--in this case 1H-1S-1N shows 4 spades with insufficient calues for a reverse.

[Fluffy]

In spain we know (and I play it) with a Brazilian name, but I suposed if you googled it you would get only portuguese text.

[arrows]

Thanks all for your answers.

A couple of more quesitons:

1. is this 1♠ response (deny spades) practically has upper-limit in strength?

2. How are the RESPONDER's rebids of 2♠, 2NT, etc. typically used?

Thanks in advance.

[MickyB]

1. If you play 1NT as 5+♠, then 1♠ is unlimited unless you find another bid for a strong 4♠333. In a Precision context I played 1♠ as including balanced game forces, then 2♣ and 2♦ were GF with a 5 card suit.

2. Same as after a forcing NT - 2NT is bal invitational, 2♠ is a strong raise of partner's minor.

It is generally a sound method, but sometimes loses out when the correct lead is found due to a lead directing double of 1♠, or even when a spade lead is successfully avoided due to the lack of a double.

This post has been edited by MickyB: 2005-January-14, 14:08

[mr1303]

There is a version in a Khamerashi system I play, which uses Intermediate Lucas 2s (also known as khamerashi 2s), so the Kaplin Inversion can be even better defined:

1H 1s

1NT = balanced
2C = Flannery
2D = Bad 2H rebid (6+ hearts)
2H = Good 2H rebid (6+ hearts)
2S = reverse

[MickyB]

mr1303, on Jan 14 2005, 08:33 PM, said:

There is a version in a Khamerashi system I play, which uses Intermediate Lucas 2s (also known as khamerashi 2s), so the Kaplin Inversion can be even better defined:

1H 1s

1NT = balanced
2C = Flannery
2D = Bad 2H rebid (6+ hearts)
2H = Good 2H rebid (6+ hearts)
2S = reverse

Isn't it an improvement to invert 2♦ and 2♥? Or maybe just add strong types into 2♦... immediate jump rebid shows 5-5, 2♦ then a minor shows 6-4?