RulesMLB Umpire Manual

First Baseman’s Mitt

Rule 3.05: The first baseman is not permitted to use a first baseman’s mitt if, in the umpire’s judgment, another fielder is positioned at first base. If the umpire determines on his own or after being prompted by the opposing manager that the first baseman is not positioned at first base, the umpire should instruct…


4.03 Exchange of Lineup Cards

Unless the home Club shall have given previous notice that the game has been postponed or will be delayed in starting, the umpire, or umpires, shall enter the playing field five minutes before the hour set for the game to begin and proceed directly to home base where they shall be met by the managers…


4.01 Umpire Duties

Before the game begins the umpire shall: (a) Require strict observance of all rules governing implements of play and equipment of players; (b) Be sure that all playing lines (heavy lines on Appendices No. 1 and No. 2) are marked with lime, chalk or other white material easily distinguishable from the ground or grass; (c)…

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