[Martee]

Obviously my communications skills lack as you all will see in my response.


1. What is the relationship of the Target Line to the Line of Flight from the perspective of a line on the ground?

Before providing my answer, allow me to point out that these questions are an out growth in trying to apply the principles (Chpt 2) to the 24 components (Chpt 7 and 10) as outlined in the Introduction (Chpt 1).

First I subscribe to the definition of the ‘Target Line’ as a straight line in the intended direction the golf ball is to travel, not the path of the golf ball’s flight.

Homer defines Line and Path (7-2) and the above statement matches. Homer also defines ‘Line of Flight’ as occurring as a vertical action (2-N-0) but in identifying, as a line on the ground appears to be correct (10-5 photos).

The only confusion as to if the ‘Target Line’ and ‘Line of Flight’ are one in the same line when projected on the ground comes from 7-5 and 10-5. In these references first the discussion is in regards to ‘Line of Flight’, the in later paragraphs the discussion is regards to the ‘Target Line’. And then we have the Text accompanying the Photos in 10-5 that reference ‘Target Line’ but show ‘Line of Flight’.

With lack of clear definition and the interchange of terms I rely on Homer’s premise that he used common terms unless otherwise defined. I did a search and discovered the following definition that I LIKE…

Target Line – An imaginary straight line drawn from behind and through the ball toward the intended target (Intended line of flight or Aim-line).

Note I was selective in my choice since in my search the majority did not indicate ‘intended’ but rather a direct line if they provided a definition at all for the terms. Also in referencing the standard dictionary, the terms also were not defined. The definition I have embraced I believe is the most fitting as to how Homer intended to use the terms. Besides I became very discourage to discover that a number of words we use in our post everyday cannot be found in the dictionary, clubshaft, clubhead, sweetspot, but clubface is there (American golf slang at its best?).

I am left to conclude that the ‘Target Line’ and the ‘Line of Flight’ are one in of the same Line. Not separate lines that are parallel, not separate lines that can be overlaid on each other, not separate lines that can have any separate or distinct relationship to each other.

This are references that state the clubface is square to the Target Line at separation (2-J-1), the clubface needs to be square to the Line of Flight only at point of separation (1-L-17), but they add little to support the statement directly that the Target Line is in fact the Line of Flight.

The interchanging of terms does take away from the clarity of the subject. Glossary definitions would have been helpful. What is obvious to one is not always obvious to another and in this case these definitions are IMO critical to moving forward in understanding other ‘Line References’. We all need to be on the same page so to speak.

I believe that question 2 and question 3 can be addressed together based on the definition of ‘Target Line’ and ‘Line of Flight’. By accepted definition they are one of the same.

2. What is the relationship of the Plane Line to the Line of Flight from the perspective of a line on the ground? (Edited - Plane line is the same or not as the Line of Flight)

3. What is the relationship of the Plane Line to the Target Line from the perspective of a line on the ground? (Edited – Plane Line is the same or not as the Target line)

Base on the references of the ‘Plane Line’ to the ‘Target Line’ or ‘Line of Flight’ in 7-5 and 10-5 along with the accompanying 10-5 photos and descriptions, one can conclude that the ‘Plane Line’ is not the same as the ‘Target Line’ or ‘Line of Flight’. It can have a relationship of being parallel (square) or across (open or closed) but it is a separate line. Also when projecting these lines on the ground you will see two distinct lines, the Plane Line and the Target Line / Line of Flight.

Though that may seem straight forward, reading 2-F confusion is created. This reference states “But herein, unless otherwise noted, “Plane Angle” and “Plane Line” always refer to the Center of Gravity application. Study 2-N.” If we read 2-N-0 we learn that the Plane Line is redefined – “Herein, Plane Line means the Impact Plane Line.”

Further if read the Glossary; we have a definition for “Plane Line - A line inscribed on the surface of the Inclined Plane passing through the Ball Location to serve as its Base Line and its center of rotation when changing its angle”.

This would lend itself to the conclusion that the Plane Line when square (parallel) to the Target Line / Line of Flight is overlaid so that only one line would be seen. Also it is possible that the Plane Line will cross the Target Line / Plane Line BUT the intersection of these lines will be at the ball.

Just a quick review of the references of Plane Line to Target Line or Line of Flight provides:

Plane Line and Line of Flight are the same (2-F with two exceptions 10-5) 2-F reference base of Inclined Plane (as Plane Line) see 7-5.

Plane Line and Line of Flight are not the same (1-L, 1-L-19, 7-5, 10-5)

Target Line and Plane Line are the same (Glossary, 1-L-17, 2-J-1)

Target Line and Plane Line are not the same (2-J-2, 7-2, 7-5, 7-10, 10-5)

If 2-F and 2-N-0 are to be accepted that the ‘herein’ trumps all other definitions for the Plane Line, it calls into question the validity and accuracy 7-5, 7-6, 7-7, 10-5, 10-6 and 10-7 along with 1-L, 2-C-1 and 2-F. Even the definition contained within the Glossary calls those chapters content into question.

Base on the above, it is impossible to answer the questions as it stands IMO. What is needed is an understanding, definition and defined relationships of the Inclined Plane. Within TGM Homer has referenced at least 3 distinct Inclined Planes all of which by definition have a Plane Line and Plane Angle.

I submit that another thread is needed to address Inclined Planes before we can answer these questions, before we can correctly put these terms context within TGM.