As a divinatory line, nine at the fourth place of Breakthrough reads within the hexagram's overall concern with the culprit's guilt exhibited at the royal court, with sincere and earnest appeal, and a consciousness of the peril in cutting the criminal off. The line occupies a place that does not match its own nature in the classical doctrine that odd places favour a firm, yang line and even places favour a yielding, yin line. Its own text, that buttocks stripped of skin, walking slowly and with difficulty, one who will not listen though the words are plain, is the particular fortune assigned to this one stage of the situation, not to the hexagram as a whole.
The fourth line corresponds by classical convention with the first line, and the two do not correspond here, since both lines share the same character. Read together with the trigram it belongs to, Dui in the upper position of the figure, the line marks the first word of the upper trigram, close enough to the ruling fifth line to be shaped by it, one stage in the six stage movement the hexagram traces from its first line to its last.
A change at this line, from yang to its opposite, is the mechanism the tradition uses to move from one hexagram to another. Flipping the fourth line of Breakthrough turns Dui into Kan while the other trigram, Qian, stays as it is, which yields Breakthrough's changing partner, Waiting (King Wen 5), the hexagram this line is recorded as transforming into.