When does the ball become dead immediately?

The ball becomes dead immediately when the batter enters the batter's box with an illegal bat. This is a crucial rule designed to maintain the integrity of the game and ensure fair play. An illegal bat can give a player an unfair advantage due to characteristics that may enhance performance or violate safety standards. When an illegal bat is detected, the play is stopped immediately to enforce the rules and prevent any potential issues that could arise from using such equipment.

In contrast, while the other scenarios involve actions that might lead to penalties or enforced rules, they do not result in the ball being declared dead immediately. For example, if a runner removes his helmet, the play continues until the next pitch or until the runner is put out. Similarly, a coach assisting a runner could lead to consequences after the play, but it does not stop the game immediately. A batted ball touching an illegal glove may result in a ruling related to the play, but again, it does not cause the ball to be dead right away. Thus, the situation involving the illegal bat is distinctly classified as causing an immediate dead ball due to the violation of equipment standards.