Doctored Ball (1904)

“Jimmy Williams made many a wild throw because he couldn’t get a firm grip on the ball that Jack Chesbro doctored. The spit ball was Chesbro’s favorite. He used to go through many a whole game without pitching a half dozen straight ones.” The Muncie Morning Star, November 14, 1904, p7

Early examples with different meanings:

Putting substances on the ball to make it hard for the pitcher to control it
— “The Altoona players tried to put Dr. Reisling out of the business yesterday by putting oil of mustard and licorice on the ball, but Doc was not making much use of the spite ball and didn’t care what the visitors put on it. Joe McDonald was the one who first doctored the ball and the next time he came to bat Doctor Reisling struck him out.” Coatesville [PA] Union quoted in the Altoona [PA] Times, July 24, 1905, p3

Using a doctored ball that could be hit farther
–“Here’s the Story of a Doctored Base Ball” (Headline). “‘In the American Association we sometimes ring in a ball constructed of a square rubber center, and wound with rubber band to the required size, when the game is going against us and it our time to bat. You can hit a ball of that kind a mile ….” Toledo club president J. Ed Grillo quoted in The Buffalo Enquirer, November 2, 1905, p10.

Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1ST USE. 1917. “The natural surface of even a new baseball is rather rough and the friction would be less on the surface made shiny by the application of talcum powder or licorice. This tends to pile up the air on the side of the ball which has not been ‘doctored’ and slow up the speed of that side” (Paul Purman, Fort Wayne [Ind.] Sentinel, July 5; Peter Morris).