This key, I discovered it in 1999. I do not believe that there is a trace in the literature. Examine the six lines and carry out this calculation:
Line 1 = YIN? count 25, if not, count 0
Line 2 = YANG? count 50, if not count 0
Line 3 = YIN? count 25, if not, count 0
The sum of the three digits gives you an indicator of interior tension (from 0 to 100%)
Carry out the same thing with the higher trigram (4=YANG gives 25, 5=YIN gives 50 and 6=YANG gives 25).
The sum will give you an indicator of external crisis.
Make the average to have a general indicator of crisis (you will see, the figure obtained is in phase with the text of all the good existing translations).
For example, the hexagram 12 (BLOCKING) gives 50% - 50%. Only one hexagram does not present any tension (it acts of the last, the 64th: Before the achievement! Guess which is only the hexagram which at 100% is tended. If you seek the 8 hexagrams who present 100% of interior tension, you will find the 35 youthful madness, 59 the conflict, 27 the overwhelming pressure, etc. Right now, you will know if the problem comes rather from you or of outside. But be careful, this trick must be supplemented by an analysis of the interior trigrams to avoid misinterpretations.