The Single Greatest Year.

[Tao_Moko]

1909 was still in a decade of economic growth(4%), pre depressions, pre WWI and the birth of the most prolific set in baseball card history. Gets my vote.

[Joe_G.]

I'm biased, but 1887 is a strong contender . . .

Cigarette pack inserts skyrocket as the industry transitions from paper packs to cardboard slide & shell. Practically every subject matter would follow including baseball.

1887 Greatness
Old Judge, Gypsy Queen, Buchner Gold Coin, K-Bats (players & team cards), Four Base Hits, as well as the first baseball currency issues.

1888 - Strong Follow-up
A&G Champions, Goodwin Champions, Kimball Champions, Yum Yums, four different SF Hess baseball issues, OJs (both cigarette cards & cabinets), more currency, and the first gum issues courtesy G&B and HD Smith (Y95 Scrapps).

[brianp-beme]

1910 is my vote, but the whole stretch from 1909 through 1912 includes a huge chunk of the Deadball era cards that a lot of us collect, and blows away all other four year stretches hands down. A beater collector like myself thanks all the producers of the various E and T cards (definitely the heyday for these ACC classifications) for their overwhelming prolific-ness during this time.

Below I have depicted just a small percentage of the sets that were available during that 4 year period.

Brian

[SD]

Goudey, diamond stars, delong, George miller, & orbits. All beautiful sets

[abothebear]

just kidding