The Self Line
The distribution of the Self line can be seen in the following arrangement of the hexagrams:
01-58-30-51-57-29-52-02
43-10-55-21-48-59-15-23
05-61-36-27-28-06-62-35
34-38-49-25-46-04-39-20
11-41-63-42-32-64-31-12
14-54-13-17-18-07-53-08
26-19-37-03-50-40-33-45
09-60-22-24-44-47-56-16
The Self line is the first (bottom) line is 8 hexagrams, as shown here in the bottom horizontal row.
The self line is the 2nd line in 8 hexagrams, shown in the second horizontal row up.
The self line is the 3rd line up in 16 hexagrams, shown here in the 3rd and 4th horizontal rows up.
The self line is the 4th line up in 16 hexagrams, shown in horizontal rows five and six.
The self line is the 5th line up in 8 hexagrams, shown in horizontal row 7.
The self line is the top line in 8 hexagrams, shown in the top row here.
The top orizontal row is remarkable for two reasons: all the hexagrams are doubled (for example, Gen over Gen), and all 8 are "6 strike." (75% of the bottom row hexagrams are "six match.")
In this arrangement, all 8 horizontal rows have the lower trigrams arranged in the Early Heaven-Fu Xi-Shao Yung sequence of yang and yin trigrams (yang having a yang line at bottom, yin having yin line at bottom). For the upper trigrams in the rows, the yang and yin trigrams are separated left and right. Fo every row, the leftmost upper trigram is the opposite of the rightmost upper trigram, and this opposite mirror is continued for each left and right pair of uppers going toward the centre.
The upper trigrams also are in opposite line for line pairs vertically, between lines 1+5, 2+7, 3+6, and 4+8.
Thus, the concept of the self line seems to be a product of this special Early Heaven arrangement. The Wild Crane system, which is based on the Later Heaven-King Wen arrangement of the trigrams, seems to have adopted the concept of the self line.