As can be seen by this set of blog entries, one purpose of this blog is to show some of the thinking and revisions that goes into design work.
Here's a Kaplanville summary:
Kaplanville is a structure that can be played after the 1H-1S like-a-forcing-notrump Kaplan Inversion/Granville. When using this, 1H-1NT is often used to show 5+Ss, forcing.
With Kaplanville, after 1H-1S, opener rebids:
- 1NT with up to 14, no five card or longer minor, and not 0-5-4-4, and not 4Ss.
- 2D with 4+Ss, using 3D to show game force with Ss.
- 2S with 4+Ss and a hand in between 2D and 3D - about 16/17-18 or 6-5+.
- 2H with 15-18 and fewer than 4+Ds, or 5-5+ with Cs and up to 17.
- 2C with 4+Ds, too good or too distributional for 1NT, or with 6+Hs.
Over 2C, responder with minimum takes preference to Ds or Hs or bids 3C with long suit and no D or H semi-fit. With 9/10+, responder often rebids 2NT or 3D, but can rebid 2S which shows own long suit. Over 2S opener bids 2NT if 6+Hs, allowing responder now to show minor suit and also H fit if holding one; without 6+Hs, opener bids 3C if 5-5+ in the reds and minimum, and bids above 3C show 15+ with Ds, establishing a game force.