The most famous example involves the Chicago White Sox in the 1960s. The following story is related by Jerome Holtzman and George Vass in Baseball, Chicago Style (Bonus Books, 2001):
It began ... in 1965 when the Sox were in Detroit for a four-game series. Tommy John was pitching for the Sox and noticed the baseballs had been tampered with.
"All the balls I got that day were like cue balls, hard and slick," John recalled. "And the seams were so low, almost nonexistent. When you're a sinkerballer you can't sink the ball without seams."
John relayed the information to manager Al Lopez who told him to bring a ball into the dugout after every inning. According to John's recollections, Lopez said, "That's okay. We'll get them when we get back to Comiskey Park."
Lopez summoned Gene Bossard, a second-generation groundskeeper who knew all the tricks. Bossard understood what had to be done and began storing boxes of balls in a small, windowless brick-walled room. He installed a humidifier. In two weeks the balls were soaking wet, moist from the humidity.
... In the four-game series at Detroit, the Tigers had hit 13 home runs ... In the ensuing four-game series at Comiskey Park from July 30 through August 2, the Tigers were swinging at the doctored balls. Suddenly, they were shorn of their power. Their longest hit in the entire series was a double.