I think it was mentioned that centering is objective, the margins of a note can be measured to the thickness of a hair. I think, from my short experience that epq and ppq are not reliant on centering, I have some notes that are not centered well yet have the ppq notation. I do think centering also plays a part in eye appeal in that the margins of a note are similar to a frame on a painting. I have seen notes that were trimmed but wether they were trimmed to make the centering better or to get rid of a rough edge I do not know, but I would not knowingly buy a trimmed note. Your question is a good one, just like toning can become desirable, and blast white loses cache, could centering become less important and off centering considered more appealing? But as far as commonality, perfectly centered notes seem much rarer than notes that are off centered, whereas pleasingly toned coins also seem rarer than coins that are not that sort of rainbow coloring book toning.
It ultimately gets at what I will do with my collection at a future time. If eye appeal based on perfect centering is actually admired by people regardless of what the grading system says, then there will be stronger demand for it and it's better for resale than less centered notes. For my collection, I always buy what I like. At the same time, I like to constantly upgrade my collection (for whatever reason) so resale is important to me. So, if eye appeal is standardized, then it's not (or less) submission worthy. That's the practical bit. Way back in college, one of my majors was Philosophy, with a strong focus on logic, so it's in my nature to question everything lol.
One extreme example I mentioned earlier to draw out my point, was of a note with half it's design cut-off with a huge void on one side. To me, that's appealing. Compared with perfectly centered designs, I think that it could be more appealing than perfect ones, but it would likely depend on the design. If it's a modern note, I'd probably want the cut-off one because it would be so different from everything else that's more easily available. If it's a very old note that's very rare, I wouldn't mind if it was off-center, as a more centered note (all else constant) would cost more than I see value in it's perfect centering (I see it similar to MS-69 vs MS-70 graded coins and their prices - to me, there's very little marginal gain in utility for that slight increase in grade/centering but huge increase in premium.).
If by "upgrade" you are buying an item in one condition, and later, buying an identical item in a better condition, that's a fast way to spend your money and make others rich. Cannot argue though as many collect that way due to several different reasons.
One of my other majors way back in college was Economics, so I pretty much only look for great deals and cross check prices - I can't help it (I was like that in childhood, too)! So, if I settle on, say, an AU condition classic commemorative because the price was too good to pass up and assuming that the condition checks out, then I'll cross that off the list, until I get all googly eyed about a better looking (or condition or what have you) one I come across. Of course, it'll have to be priced well and preferably below average, and they're typically problem-free raw examples. But yeah, I always look at potential purchases alongside their opportunity cost. That's a large reason why I don't like to submit coins to TPGs unless it's well worth it - I can buy so many awesome coins instead lol.
As Insider brought up, is there any recommended literature on centering on notes? Specifically, for how the average, above average, etc. centering is defined. Does this note have average or below average centering? Something else?
I would say average. Right side and bottom match, the top is wider and the right side is too wide and out of proportion to the others.
http://admestamp.com/store/centering.html http://www.ezstamp.com/ezgrader/index.htm http://www.stampauthentication.com/Grading.html http://appshopper.com/reference/stamp-analyser http://www.iosnoops.com/appinfo/stamp-analyser-for-iphone-and-ipad/777226676 The old school, I have a couple of Scott's and Harris gauges for centering.
Centering plays a bigger part in common notes, modern notes. On older, rarer large-size Nationals and Obsoletes, good centering is just a bonus and adds little value compared to just being able to find a decent example.
The terms average or above average centering are specific to the note type. As an example, 1928 1.00 United States Notes are notorious for bad centering on UNC notes. The vast majority have uneven margins. One of those notes described as having above average margins would mean not perfect but better than usually found. MPC is another example of a series of notes where centering is usually poor so above average centering is scarce. Poorly centered notes of these series are described as having average centering to indicate that it is how the notes are commonly found. A note so badly centered that part of the design is cut off is an error. Errors live by their own rules.
Thanks, that answers much of my Q's. I thought it was odd that "average" would even be used as a general marker across all notes relative to perfect centering. Thanks for clarifying on the errors bit, that makes sense, too.