When B1 takes a couple of steps towards first base after a pitch is called a strike, what does the umpire do if B1 returns immediately to the batter's box?

When a batter, such as B1, takes a few steps towards first base after a pitch that is called a strike and then promptly returns to the batter's box, it reflects a moment of miscommunication or a minor lapse in judgment rather than an outright action that would justify penalizing the batter. In this situation, since B1 returned to the batter's box before the next pitch is delivered, the count remains unchanged. As a result, B1's count will still be 3-2.

Charging an additional strike or declaring B1 out would not be appropriate in this scenario, as the batter has not violated any rules regarding the count or their position in the batter's box. In baseball, the concept of being out is reserved for more definitive actions that involve interference or a failure to return in time, which does not apply here. Ruling a pitch as a ball would likewise be inappropriate because the original call was a strike, and the batter's subsequent actions do not alter that ruling given he returned to the box in good faith. Thus, under these circumstances, the most accurate outcome is that B1's count remains at 3-2.