[steve2005]

I'm looking for a basic Kaplan Inversion write-up.
I've googled It and the only write-ups I found involved Gazilli and transfers.
I'm looking for it in a Precision context, so Gazilli is a bit of an overkill. It is understandable why people using 2/1 would throw Gazilli in there.

For those who don't know the Kaplan Inversion or Kaplan Interchange in it's simplest form involves switch the 1♠ and 1NT responses to 1♥. The main goal is to handle Flannery hands (intermediate hands with 5 hearts and 4 spades).
So 1♥-1♠ is artificial showing 0-4 spades and acts like a forcing 1NT.
And 1♥-1NT shows 5+ spades and is forcing for 1 round.
Usually 1♥-1♠-1NT is used to show hands with 4 spades.

I am looking for something that is mostly natural as a simple way to show Flannery hands without using up 2♦ bid.
Need bidding after 1♥-1♠ and 1♥-1NT.

If anyone can post a link to or a write-up on basic Kaplan Inversion it would be appreciated.

[mw64ahw]

This is what I play non-precision, but you can adapt to show some of opener's more shapely hands. For example 1♥-1♠-2♠ becomes 5♣♥ max.
1♥-1♠ 0-4♠ weak, 5+♠ GI, 3♥ lim
.. 1N Balanced, 4+♦
.... 2♣ Which? - use with 5+♠ GF
...... 2♦ 4+♦
...... 2♥ Balanced
.... 2♦ to play
.... 2♥ 3♥ 8.5 mod. losers
.... 2♠ 5♠ GI
.... 2N 6♠ GI
.... 3♣ to play
.... 3♥ 3♥ 8 mod. losers
.. 2♣ 4+♣
.. 2♦ 4♠, 6♥ GF, 4+♦ GF
.... 2♥ pref.
.... 2♠ pref.
.... 2N 4♠ limit raise
.. 2♥ 6♥
.. 2♠ 4+♣ GI+
.. 2N balanced 18-19, 4+♦ GI
.. 3♣ 4♣6♥ Intermediate
.. 3♦ 4♦6♥ Intermediate
.. 3♥ 6♥ GI
.. 3♠ 6♥4♠ GF
.. 3N to play

1♥-1N 5+♠ weak

[awm]

1♥:
-- 1♠ = 0-4♠, less than GF values, could include 3♥
-- 1NT = 5+♠, any strength
-- 2♣/2♦ = natural, GF

1♥-1♠:
-- 1NT = 4♠
-- 2♣ = 4+♣ or 3523
-- 2♦ = 4+♦ or 3532
-- 2♥ = 6+♥
-- 2♠ = 5♠,6+♥
-- 2nt = not really needed; maybe 0544 maximum?
-- 3♣/3♦ = 5+ minor, maximum to not open 1♣
-- 3♥ = usually 7♥, maybe very max 6♥
-- 4♥ = to play, very long hearts

1♥-1♠-1NT:
-- Pass = rare, most likely 2155 with less than invite
-- 2♣/2♦ = natural normally six-card suit, not invitational
-- 2♥ = normally 2♥, very NF
-- 2♠ = 4+♠ or 31(54), less than invitational
-- 2nt = invite with no fit
-- 3♣/3♦ = natural invite
-- 3♥ = three-card limit raise (with less than four spades)
-- 3♠ = four spades, invitational
-- 3nt = to play (rare, would usually respond 2m)
-- 4♣/4♦ = shortness, agreeing spades


1♥-1NT:
-- 2♣ = 4+♣ or 2533, less than 3♠
-- 2♦ = 4+♦ and less than 3♠
-- 2♥ = 6+♥ and less than 3♠
-- 2♠ = 3♠ and minimum, or 4♠ and VERY minimum
-- 2nt = 4♠ and extras, or 3♠ and shortness somewhere and not minimum
-- 3♣/3♦ = 5+ minor, maximum not to open 1♣
-- 3♥ = 7♥ or 6♥ very maximum
-- 3♠ = 4522 and a good hand
-- 4m = void with 4-5♠
-- 4♥ = to play, very long hearts
-- 4♠ = 5611

1♥-1NT-2♣:
-- 2♦ = invite with 6+♠ or invite with 4+♣ or any GF
-- 2♥ = usually two hearts, very NF
-- 2♠ = 6+♠ less than invite
-- 2nt = natural invite
-- 3♣ = 4+♣ game force
-- 3♦ = 5+♦ invitational
-- 3♥ = 3-card limit raise
-- 3♠ = game force with a very good 6+♠
-- 3nt = to play

1♥-1NT-2♣-2♦:
-- 2♥ = 4+♣ minimum
-- 2♠ = 2533 minimum (now pass is to play, others GF)
-- 2nt = maximum with 4♣ (there is no maximum with 2533 as this opens 1nt); continuations natural
-- 5+♣, accepts an invite

1♥-1NT-2♣-2♦-2♥:
-- Pass = invite content to play in 2♥
-- 2♠ = invite with 6+♠
-- 2nt = puppet to 3♣; signoff or slam try in clubs
-- 3♣ = game force, normally 3+♣ and looking for diamond help
-- 3♦ = game force 5+♦
-- 3♥ = game force 3♥
-- 3♠ = game force long spades but not good enough for 3♠ over 2♣

1♥-1NT-2♣-2♦-2♥-2NT-3♣:
-- Pass = invite with clubs
-- 3X = cuebid for clubs

1♥-1NT-2NT (spade raise with extras):
-- 3♣ = asking, at least game interest
-- 3♠ = very bad hand

1♥-1NT-2NT-3♣:
-- 3♦ = 3♠ and short clubs
-- 3♥ = 3♠ and 6♥ and extras
-- 3♠ = 3♠ and short diamonds
-- 3nt = 4522 and very maximum
-- 4♣/4♦ = 4♠ and short in the bid suit