Prior to the Pre-Integration Era ballot in 2015, Jay Jaffe of Fangraphs expressed his opinion on Doc Adams’ candidacy in his article “Breaking down the Hall of Fame’s Pre-Integration Era ballot, Part 1” in Sports Illustrated. Below is an extract from that article.

Doc Adams, pioneer

Roll over, Abner Doubleday, and tell Alexander Cartwright the news. No less an authority than MLB official historian John Thorn called Daniel Lucius Adams “first among the Fathers of Baseball” in a 1993 essay for Total Baseball and “the most significant figure in the early history of baseball” in his 2011 book Baseball in the Garden of Eden. Adams—who lived from 1814 to 1899, graduated Yale and Harvard Medical School and practiced medicine (hence the nickname)—is the man who bears the true responsibility for setting the bases 90 feet apart and for creating the shortstop position. Additionally, he helped to standardize nine­ man lineups and nine­ inning games—innovations inaccurately credited to Cartwright on his Hall of Fame plaque—as well as the “fly rule,” which eliminated balls caught on one bounce from being automatic outs.

Adams began playing base ball (distinct from rounders or town ball) with the New York Base Ball Club as a bit of post­work exercise with fellow medical professionals in 1839. He joined Cartwright’s New York Knickerbockers in 1845, and from ’47 to ’61, he served in various executive capacities (president, vice president, treasurer or director) for the club, via which he introduced changes in rules and equipment. Via Thorn in his SABR profile of Adams (a revised version of the aforementioned 1993 essay):

The advent of the short fielder, or shortstop—the position created in 1849 or ’50 by Adams—was a crucial break with rounders. “I used to play shortstop,” he reminisced, “and I believe I was the first one to occupy that place, as it had formerly been left uncovered.” But when Adams first went out to short, it was not to bolster the infield but to assist in relays from the outfield. The early Knickerbocker ball was so light that it could not be thrown even two hundred feet, thus the need for a short fielder to send the ball in to the pitcher’s point.

Adams oversaw the making of balls via scraps of horsehide wrapped around cut up rubber from galoshes, and of bats as well. The standardization and refinement of these things is what helped make baseball a national game. “[W]e pioneers never expected to see the game so universal as it has now become,” he said in 1899, shortly before his death. While Thorn made clear in Eden that other men such as Louis Fenn Wadsworth and William Rufus Wheaton also played crucial, underappreciated roles in establishing the basics once attributed to Cartwright, it’s clear that Adams’s pioneering work has been overlooked for far too long. If he’s good enough for Thorn, he ought to be good enough for Cooperstown.