[DinDIP]

Two systems that I'm aware of have gone part of the way down the path of taking potential problem hands out of a strong 1C opening:
* In Cobra, Lindelof's CAD (computer-assisted design) system, a 2N opening shows a two-suited hand with 0-1S, the playing strength for a 1C opening (18-22 points) but marginal high cards (typically 13-16). The idea was to avoid S preemption by the opponents.
* In The Way Forward, an English symmetric system from the 90s (available at http://www.clairebri...way_forward.doc), opened 1S with 9-15 and 4+S while 1H was 11-19 with 5+H. One reason for this was to avoid competition after a 1C opening when they hold spades and we hold hearts. Another was to avoid the problems that can arise with showing hands with 5+H if 1C-1D-1H is a relay with 19/20+. (My solution is to play 1C-1D-2C as ASPRO, which has its own costs and benefits.) As a consequence they have a very neat structure after 1C-1D and after 1C-1D-1H-1S. Well worth looking at.

David