In this system, 1D makes up for a mix of hand types by having a small range of values. The 2D opening has responder well placed to judge the hand, whether or not the opponents enter the bidding.
1C as Cs or 19+ or almost either
1C: Cs or Big, either
a) 5+Cs unbalanced, no 4cM, 10+
b) 5+Cs unbalanced with a 4cM or 4-4-1-4 exactly, 10-13
c) 19+ any
d) 17-18 balanced, no 4cM, 4+Cs or 3-3-4-3 exactly.
1D: 2+Ds, either
a) 11-13 balanced (can have a 5cM, even a 5-4-2-2 with a 4 card minor)
b) 5+Ds unbalanced, no 4cM, 10-15
c) 5+Ds unbalanced with a 4cM or any 4-4-4-1 with 4Ds, 10-13
1M: 14-18, 4+ major, if balanced 16-18
1NT: 14-16 balanced, no 4cM if 16
2C: 10-13, 5-4/4-5+ in majors
a) 17-18 balanced with 5/6Ds, no 4cM
b) 16-18 with 5+Ds, unbalanced, no 4cM
2M: (8-9)10-13, 5+ major, if just 5 must have singleton and not 4+ in other major
2NT: 10-13, 6-5/5-6+ in majors
The 2D opening has responder super well placed to judge the hand, and responder can pass 2D with a bust. The 1C opening spans from 10+, but the 14-16 range is isolated to 5+Cs unbalanced with no 4cM, and responder will be able to consider the 1C opener mostly in the 10-13 or 17+ range. 15s with 6+Ds should upgrade into the 2D opening, keeping 1D limited. This is a system that will win team matches against top opponents when the hands fit the methods.