A pitcher earns a strikeout when he puts out the batter he is facing by throwing a ball through the strike zone, "defined as that area over homeplate (sic) the upper limit of which is a horizontal line at the midpoint between the top of the shoulders and the top of the uniform pants, and the lower level is a line at the hollow beneath the kneecap", which is not put in play.
A pitcher earns a strikeout by getting the batter out with a pitch that lands within the designated area called "strike zone." The strike zone includes the space over homeplate where the upper boundary is at the midpoint between the top of the shoulders and the top of the uniform pants, and the lower boundary is at the hollow beneath the kneecap. This ball does not count as part of play.