[greco827]

Pat,

That's a great spreadsheet, which certainly tells a story. What I am thinking is more along the lines of breaking the Piedmont 350 series into sub-series, each associated with the print groups. Since Piedmont was the flagship brand of ATC, and PD350 is the most common, and as such, assuming it was the first to be released (priority 1), breaking it into subgroups would bring the timeline of which cards were printed in what order into a bit more fine focus.

Group 2 for instance, has a ton of various backs. However, not all of PG2 cards have each of the various backs.

Using Mike Mowrey as an example ... Mowrey was traded in August 1909. Other than Piedmont and SC, he and Lundgren, who was released in May 1909, are in none of the same sets. Lundgren has a Carolina Brights and EPDG back, and Mowrey has neither. Mowrey however, is included in SOV350 an Tolstoi. Now this is oo small a sample size to draw any conclusions, it leads towards CB and EPDG being printed earlier in the PG2/350 series than Sovereign 350 (FG) or Tolstoi.