[Abravefan11]

Craig - Thank you for confirming the Turner and including the scan. It’s confirmed on the site and added to the searchable database.

Here is an explanation of the two shaded categories on Craig's spreadsheet you asked about. If something isn't clear, please ask me a follow up.

Impossible or Very Unlikely to Exist
By studying the confirmed subjects we know when certain backs were printed and with which subjects. This allows us to predict that a front/back combo is not possible with a great deal of certainty.

For example: American Beauty 350 (Frame), Carolina Brights and Cycle 350 backs were only printed using subjects from print group 2 and 5. So finding a subject from print groups 1,2,4 or 6 with this back is “impossible or very unlikely.”

Here are a couple of easier “impossible or very unlikely” examples. Subjects printed with 150 Series backs will not be found with 460 Series backs. Or a major league subject will not be found with an Old Mill Southern League back.

Probable No-Print
The main difference between these and the “impossible or very unlikely” combos, is that these subjects were being printed during the same time frame as the backs in question. For example over 150 Subjects were in production during the print group 1 time frame, but only 34 were printed with the Sweet Caporal 150 No.649OP back. Therefore we classify the other subjects as “Probable-No-Prints” because theoretically they are possible, but not likely given what we know.

A number of different factors are used when determining if a subject should be classified as “Possible-but NOT confirmed” or a “Probable No-Print.” We try to be cautious and leave subjects on the probable list until we have good indicators to move them to the probable-no print list. A few months ago we found a solid link between 75 subjects and three backs that led us to move them all from possible to probable no-prints on these three lists.

With all that said the checklists are a constant work in progress. Since the site went live a little over a year ago, we've had over 100 new front/back confirmations added. We’re working to find other solid indicators to move subjects from possible to probable-no print, and always open to a subject moving the other way. By no means do we claim the checklists to be infallible, but that is what we're working toward whether attainable or not.

Thanks again to everyone for their help.