There is nothing like a 17-inning loss to get a manager’s emotions running hot. When the Red Sox and Twins played a 5-hour 45-minute marathon game, June 17, 2019, Red Sox manager, Alex Cora watched his team walked off by a game winning single by Max Kepler. But earlier in the 17th inning, Cora had a heated argument with home plate umpire Jeremy Rehak when Twin’s Eddie Rosario fouled off a pitch attempting to bunt. Cora thought Rosario was out of the batter’s box when he made contact with the pitch.
According to the rulebook, a batter is out “if he hits the ball with one or both feet on the ground entirely out of the batter’s box.” Replays clearly show that Rosario was well within the box because the batter’s box includes the lines. Either Cora had a terrible look at the play or didn’t know the rule about the lines being part of the box. Cora later apologized to the umpires for allowing his emotions to take over. He didn’t admit to not knowing the batter’s box rule but he knows it now.
Here is the rule interpretation from the MLB Umpire’s Manual
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 assumes a position in the box. There is no penalty specified for violation other than the batter shall be instructed to stay within the batter’s box if brought to the attention of the umpire, or—if blatant or recurring violation—upon immediate direction of the umpire. If a player, after so directed by the umpire, blatantly refuses to comply, the player is subject to ejection. See Official Baseball Rule 5.04(b)(5) [former OBR 6.03]. Under Official Baseball Rule 6.03(a)(1) [former OBR 6.06(a)], if a batter hits a ball (fair, foul, or foul tip) with one or both feet on the ground entirely outside the batter’s box, the batter shall be declared out. (See Official Baseball Rule 6.03(a)(1) [former OBR 6.06(a)].)
TO CLARIFY: There are two different rules regarding the batter’s position in the batter’s box. Rule 5.04(b)(5) [former Rule 6.03] requires the batter to have both feet within the batter’s box when assuming an initial position in the box prior to hitting (no portion of the foot may be outside the line under this provision, although no penalty is prescribed other than the instructions given above). Rule 6.03(a)(1) [former Rule 6.06(a)] provides that the batter be declared out if he hits the ball with one or both feet on the ground entirely outside the batter’s box. (So long as any part of the foot is touching any part of the line when the batter hits the ball, he is within the rules.)
The “out of the batter’s box” play is most commonly misinterpreted when a player steps on home plate. This happens often on a hit and run or a bunt. But a batter may step on the plate while making contact with the pitch as long as he has part of his foot inside the batter’s box.
If the batter is deemed out of the box while making contact with the pitch, he is called out and the ball is dead.
Watch Ted Barrett explain the rule.