Rule 3.03 [former Rule 1.11]: A pitcher may wear a jacket while a base runner. A pitcher may not wear a jacket while batting. No other player is permitted to wear a jacket while a base runner, a batter, a defensive player or a coach on the baselines. If worn, the jack-et must be buttoned.
Umpire Interpretations of Major League Baseball
Rule 3.04 [former Rule 1.12]: The catcher may not substitute a fielder’s glove or a first baseman’s mitt for a catcher’s mitt during the progress of the game or on any individual play. The catcher may use a catcher’s mitt with a vinyl fluorescent piece attached.
Rules 3.04, 3.05, 3.06 [former Rules 1.12, 1.13, 1.14]: Official Baseball Rules 3.04, 3.05, and 3.06 [former OBRs 1.12, 1.13, and 1.14] describe proper glove measurements and should be enforced for all gloves used in Major League games. The key measurements are “J” and “A” lines (see Diagram Number 4 in the Official Baseball Rules). […]
Rule 4.03 [former Rule 4.01]: Each manager should write the name of each eligible player on the face of his club’s batting order card in addition to furnishing the starting lineup. However, a manager’s failure to list an eligible player does not prevent that player from enter-ing the game, nor is such failure grounds for protest, […]
Rule 5.01(b) [former Rule 5.02]: If a batted or thrown ball inadvertently goes inside a player or coach’s uniform (or lodges in the catcher’s face mask or paraphernalia), the umpire shall call “Time.” He will, using common sense and fair play, place all runners in such a manner that, in the umpire’s judgment, will nullify […]
Rule 5.02 [former Rule 4.03]: Official Baseball Rule 5.02 [former OBR 4.03] provides that when the ball is put in play at the start of or during a game, all fielders other than the catcher shall be on fair territory. In particular, when holding a runner on first base, the first baseman shall position himself […]
7. BATTER’S POSITION IN BATTER’S BOX Rules 5.04(b)(5), 6.03(a)(1) [former Rules 6.03, 6.06]: When the batter assumes a batting stance in the batter’s box, he shall have both feet entirely within the batter’s box; i.e., no part of either foot may extend beyond the outer edge of the lines defining the box when the batter […]
8. FLY BALL STRIKING TOP OF OUTFIELD WALL Rule 5.05(a) [former Rule 6.09]: Unless provided otherwise by local ground rule, a fair fly ball striking the top of the outfield wall and bounding back onto the playing field shall be treated the same as a fair fly ball that strikes the outfield wall and rebounds […]
9. ABANDONING BASE PATH (INCLUDING AFTER THIRD STRIKE NOT CAUGHT) © MLB Umpire Manual Rules 5.05(a)(2) Comment, 5.09(b)(2) Comment [former Rules 6.09(b) Comment, 7.08(a) & Comment]: Under the Comment to Official Baseball Rule 5.05(a)(2) [former OBR 6.09(b)], a batter who strikes out on a third strike not caught is treated differently than the plays relating to […]
10. CATCHER’S INTERFERENCE Rules 5.05(b)(3), 5.06(b)(3)(D), 6.01(g)[former Rules 6.08(c), 7.04(d), 7.07]: Under Official Baseball Rule 5.05(b)(3) [former OBR 6.08(c)], if catcher’s inter-ference is called with a play in progress, the umpire will allow the play to contin-ue because the manager may elect to take the play—unless the batter reaches first base and all other runners […]