» June 9, 1900: A forerunner of today’s players’ union is organized in New York. Three delegates from each NL team launch the Player’s Protective Association and elect Chief Zimmer president. Their goal is to negotiate contracts and rules changes.
» February 26, 1901: NL officials meet with Charles "Chief" Zimmer, Pittsburgh catcher and the president of the PPA, and agree to contract concessions granted by the AL for NL players who will agree not to sign with AL clubs. Zimmer promises suspensions for PPA jumpers to the AL.
» May 21, 1901: Giants fractious owner Andrew Freedman accuses umpire Billy Nash of incompetence and bars him from the Polo Grounds. Pirate Chief Zimmer and the Giants John Warner are forced to officiate. Mathewson then wins his 7th straight, 2-1, but his scoreless streak stops at 39 innings when the Bucs score an unearned run in the 9th.
» June 11, 1903: Following a win by Ed Doheny, Pittsburgh gets back on the shut out track when Deacon Phillippe throws his 3rd straight whitewash, defeating Brooklyn, 9-0. His batterymate Ed Phelps is 3-for-3 with a stolen base: as noted by Joe Elinich, Phils' manager Chief Zimmer calls Phelps, "the best catcher in the game" and "a coming star."
» September 9, 1909: George "Moon" Gibson of Pittsburgh catches his 112th consecutive game, breaking Chief Zimmer's 1890 record. His streak will end at 140.
» July 29, 1921:
As part of Cleveland's 125th anniversary celebration, Cy Young, 54, makes a two-inning appearance on the mound in an old-timers' game. Chief Zimmer, 60, is his catcher.
» September 20, 1925: In Cleveland, the Chicago Cubs and Cleveland old-timers play a 6–6, 8-inning tie. The lineups include Three Finger Brown, Jimmy Archer Artie Hofman, Mort Scanlan and Dutch Meier for Chicago; For Cleveland, Larry Nap Lajoie, Dode Paskert, Chief Zimmer, Cy Berger, Cy Young, and Joe Delahanty. The game benefits the Amateur and Old-timer's Baseball Association of Cleveland: "This association employs a doctor to look after the injuries of any boy hurt in baseball in that district." Before boarding the train for Cleveland, Brown throws batting practice for the Cubs at Chicago.