What it means
Krishnamurti Paddhati takes every point down four rungs: sign, then nakshatra (star), then sub, then sub-sub. The sub is Krishnamurti's own addition. Each nakshatra is cut into nine subs in proportion to the Vimshottari dasha years, so the slices are deliberately unequal — Venus's sub is 2°13'20" wide, the Sun's only 40'.
How it is read
In KP the sub-lord settles what the sign and star only set up, and the cuspal sub-lord — the sub-lord at a house cusp — is what the system consults when a question belongs to that house. That is the whole method in one sentence, and it is why two points barely a degree apart can answer differently.
What to watch for
KP is a school, not a refinement everyone shares. It uses its own ayanamsa (KP-Newcomb) and Placidus house cusps rather than Lahiri and whole-sign houses, so a KP chart will not agree with a standard Vedic one — a planet can sit in a different house entirely. Neither is wrong; they are different systems.