In light of the discoveries in the other thread, here is the working version of the text blocks.  When we've got some consensus we can ask Foul to update it.  You'll have to give him your real name if you want credit for the Fourth Plus discovery/research.  

# Fourth (Aug 1979)

   * Wizard logo
   * Cover art is of a collection of monsters, including a small red dragon, a unicorn, and a troll
   * "Advanced D&D" is in an angled yellow banner, top left corner; the red letters of "Advanced D&D" have black highlights, and there's no "TM" designation after it
   * "Monster Manual" title is at the top
   * "Advanced D&D" is in white lettering on the spine.  Now states "by Gary Gygax"
   * ISBN on spine, rear cover, and bottom of title page
   * Red endpapers/flyleaves
   * States "4th Edition, August 1979" on the copyright page
   * Considered the "final" version, with all the errata incorporated
   * This version, like the Third+ print above, is fairly rare
   * Catalog page has prices for Star Probe and Star Empires
   * Thanks to Eric Banks, Michael Deaton, and Adrian Newman for help with this info, and to Adrian Newman for the scan
     
# Fourth Plus (Aug 1979)

   * Wizard logo
   * Cover art is of a collection of monsters, including a small red dragon, a unicorn, and a troll
   * "Advanced D&D" is in an angled yellow banner, top left corner; the red letters of "Advanced D&D" have black highlights, and there's no "TM" designation after it
   * "Monster Manual" title is at the top
   * "Advanced D&D" is in white lettering on the spine.  Now states "by Gary Gygax"
   * ISBN on spine, rear cover, and bottom of title page
   * White endpapers/flyleaves
   * States "4th Edition, August 1979" on the copyright page
   * Considered the "final" version, with all the errata incorporated
   * Hydra illustration is smaller than the Fourth
   * Catalog page has no prices for Star Probe or Star Empires

Way to go.

deimos3428 wrote:    * White endpapers/flyleaves (both versions have been spotted)

What's "both" in that context, though? hopefully not an obvious question...

Would still quite like to see some indication of changes between prints when listed thus (filled vs. hollow bullet point?) and know that I spent quite a time bitd when reading through/comparing to try to spot each actual change amongst the full specifications.

Ah... some people are too honest for their own good.

Cheers and  'grats for being able to type up that much on a 'phone at all whilst presumably flicking backwards and forwards; albeit having small paws probably helps somewhat.

There needs to be a mention of the Random House addition for the white leaf.

All in all, though, I still think your initial diagnosis is probably correct in that white 4ths are really 5th minus. The Random House addition is a pretty major thing, probaly involving legal stuff. There are too many reasons stitching could be different, or even the same, from one print to another. 'Circumstantial evidence' as it were.

I'd also be hesitant to make the final diagnosis until we hear from more than one or two people on their copy just to make sure that there are NOT actual white 4ths in addition to this 'new' breed.

Patience, Grasshopper!  

SimperingToad wrote:There needs to be a mention of the Random House addition for the white leaf.

I had considered that, but it's also an overhaul that needs to be mentioned in all three books.  We'll get there once we sort out where this one goes!

SimperingToad wrote:All in all, though, I still think your initial diagnosis is probably correct in that white 4ths are really 5th minus.

TheMilford wrote:5-minus might be more accurate in this case.

I wish that were the case, but I can't agree.  I'll try to summarize all the points I considered in coming to this conclusion, for purpose of healthy discussion.  

Cover

The traditional marker between the 4th/5th printings is there, specifically the lack of a TM symbol.  That heavily favors the book as a 4th variant in my opinion.  It has the weight of historical classification behind it -- we should not change things lightly.  But the material/inks used and the change in flyleaf color match the 5th and favor that designation.  (These are the side-effects of the move to Random House.)

In my opinion, the cover is a wash.

Interior

The catalog page is nearly identical to the 4th red; the 5th is completely different.  But outside of the catalog page, the 4th white does resemble the 5th more.  It's undeniable.  There is the hydra resizing, and the addition of the Random House line.  

However, the other known case of a MM variant, the 3rd plus, is identical to the 3rd, text-wise.  Ideally the book under consideration at the moment wouldn't be classified as a variant at all but we don't have that option, something I'll touch on later.  

Given that, I think these two points are also a wash.

Binding

That which brings the Cover and Interior together seems like a minor issue, but it turns out to be very signficant here.  Note that in every other case where it changes, across all three books, we denote a new full printing.  There are a fair number of these cases.

In the MM chronology specifically, each time this occurred TSR was kind enough to confirm it with printing numbers on the copyright page.  So that strongly favors it being designated as a 4th variant, as the 5th must be distinct from that which came before.  While a boundary between the 4th red and 4th white is not required, a boundary between the 4th white and the 5th is required.

I think that settles it conclusively, I really do.

History and Identification

One of the things we strive for when constructing these printing chronologies is easy identifiers for determining the printing/variant.  It's no good if the difference is the color of the interior of the spine or something nobody will ever see.  That's why looking at stitching is a last resort, and why this hid for so long as being identical to the 4th red!  

Regarding the 4th/5th boundary, the TM/No TM distinction has to date been the best way to distinguish a 4th from a 5th at ten paces.  Putting this book with the 5ths ruins that.

Nail in the coffin for the 5th minus, in my opinion.


Full Printing?

Ok, so why don't we just shift everyone down one then?  That would be ideal!  The 4th white is the 5th, the 5th is the new 6th, etc.  Well we can't -- we're boxed in.  This is the point I alluded to above.  

Starting with the 9th printing, TSR started labelling the printings again.  We need to respect that, so there's no room left to add another between the 4th and the 9th.  

It must be a variant, can't be a 5th variant, so it's a 4th by default.

Other Factors

I haven't the ability to measure, but dimensions should be considered as well.  I would not be surprised to discover the 4th white is slightly taller, just as an example.  I believe the first Random House PHB printings were noticeably taller.

Of course, some other point of distinction may exist, as yet uncovered.  That's always the case.  I completely agree with SimperingToad's last point that we need to be patient and see what else might be out there.

Is there any difference in the content of these printings? (Changes in the rule system, corrections to the text, additional material or removed material?).