Vinyl heresy-overhang induced distortion is not that important

The odd thing is that Raul's native language is Spanish, or I assume it to be.  In Spanish and other Romance languages, the verb usually does not come last in a sentence.  Truth be told, I usually understand Raul, but I did not understand all the nuances of his latest diatribe against me, as noted above.  I just tried to get the gist of it. 

What Raul was saying is:
I (LewM) cannot hear the differences afforded by exact proper alignment, because:
(1) I use "tubes". (Note that he is essentially incorrect regarding my Beveridge system.)
(2) Raul once owned an underhung tonearm (the RS Labs RS-A1).  He didn't like it.
(2) I am not a trained listener, as he is.  None of us is trained, but Raul is trained.  He trained himself.
(3) We should enjoy the "music", even though we are not worthy.

So, I ask Raul or anyone else to produce data to support his underlying assumption that proper alignment according to one of the three standard algorithms (Lofgren, Baerwald, Stevenson) produces less or lower audio signal distortion over the course of playing a typical LP than would be the case if the alignment did not conform to any of those standards. Here we have to be careful, because, as I noted, it is fairly easy to misalign the cartridge to such a degree that there are no/zero null points achieved across the entire surface of an LP.  Whereas, there are probably un-documented alignments that do result in 2 null points.  So, we have to decide on what alignments to compare. I have done an internet search to find out whether there is a published paper on this subject, from the AES, for example, and I don't find any.  Baerwald's alignment was published in 1941!!!  What one would do is to measure THD at the output of a phono stage vs time (t) from the start of play to the run-out grooves, using a test LP that encodes a single pure tone.  Then plot THD vs t for two or more alignments.  If alignment is critical, then THD should be minimal at the exact moment when the cantilever is tangent to the groove, etc.  The time-based data could be converted to THD vs distance from outermost groove to innermost groove.

The funny thing is, I had the serendipitous experience that leads me to question the need for precise alignment using Baerwald, Lofgren, or Stevenson, only about 2 weeks ago.  And it was unexpected. But I'd like to know "the truth", or a better approximation of it.

Lewm;
Great post. I believe that there have been some scholarly articles published in Stereophile on the subject. The popular alignments do a fairly good job of minimizing average distortion over the course of the side depending upon multiple factors; primarily inner groove circumference and whether crescendos toward the end of the side-if you are a classical music fan-should be optimized. 
I totally buy into the notion that having two null points and having them strategically placed apart from each other with the lowest possible distortion in between and beyond them is preferable in an abstract world. My OP was to discuss relativity of this topic in a real-world audio system. 

I think we all knee jerk into conflating distortion with noise or some other objectionable sound.  In reality, distortion is only the difference between the input and the output of a device.  A parametric equalizer, which virtually every mastering engineer uses, technically distorts the sound, but in a way that the engineer believes will make it more pleasing to the ear, not less.  So when a cartridge is not optimally aligned, while I agree there may be more distortion over the arc, it may well be preferable to the listener, unless it causes mistracking, which I would think everyone would find objectionable.  Most turntable manufacturers and recognized experts, for whatever that's worth, seem to say that the sound will be better with as close-to-perfect alignment as possible.  Once you get to a certain level in this hobby, "better" becomes very subjective.  Even if distortion is measurably higher in a given component, one may prefer the sound to another better-measuring component.  

Actually, Spanish has considerable fluidity w.r.t. Subject Verb and Object.

Just about any combination of SVO is possible, depending on which part of the utterance you're putting the emphasis on. Not too much room for ambiguity, given common sense construal of the sentence and particularly if a "personal a" is involved, indicating which is the Object.

fsonic et al, What is measured is the tracking angle error, the degree to which the cantilever deviates from tangency.  All the plots I have ever seen plot distance from outer groove to inner groove as a function of the angle by which the cantilever is not tangent.  Thus you see a horizontal line representing the x-axis, labeled "0", to indicate zero tracking angle error.  Then you have on the y-axis positive numbers above the x-axis and negative numbers below the x-axis, to indicate that the tracking angle error can go either positive or negative with respect to its vector direction.  Then we audiophiles conflate these data with audio signal distortion.  But I have never seen any experimental proof that the two are linearly correlated.  In the modern era, there is no one who would bother to do that, because we live in the era of BS rules.  In the era from the 50s through most of the 70s, there were reputable audio companies and publications that might have conducted such work.  Shure, for example, published beautiful treatises on cartridge design and performance, in those days.  Early Stereophile did some nice stuff, and so did Audio Magazine.  Then there is/was the Audio Engineering Society.  

Certainly, it makes sense to maintain tangency as much as possible. I don't dispute that that is an attractive idea.