This graph shows the circle graph which shows the moment by each rod component at the point of grip front, that is the end of action length, on the converted to (new) rod.

This graph can be viewed as how the rod caster (fisher) feels the contents of moment force at rod hand.  The author named this as "Feels of cast",  that means how a caster feels bamboo, or fly line more  in the casting.  Such a rod with more percentage of bamboo weight, may be felt as rather a heavy rod and feels dull in casting with less feeling of fly line, under a certain G (4 e.g.) speed with standardized line length.  Oppositely, with more fly line percentage, a caster can feel fly line weight  more than bamboo weight on his hand while casting.

The author's measurement is to try to this ratio almost equal between bamboo and fly line under 4G speed and standardized length of line to fish, e.g. 40 ft for #4 line.

Standard is so far at each user's discretion.