A baseball statistic that represents a ratio of the number of times a batter strikes out to their plate appearance. This number can be calculated by dividing a player's total number of plate appearances by their total number of strikeouts. For example, if a player has 89 strikeouts and 688 plate appearances their PA/SO would be 7.73, which suggests that for every 7.73 plate appearance the batter has one strikeout.
Plate Appearances per Strikeout (PA/SO) allows a defensive team to examine the opposing team's lineup for hitters who are more prone to strikeout. This typically means that these players, when batting, are typically more aggressive than your average hitter. This permits the pitcher to approach the batter with more options, often throwing more balls out of the strike zone in the hope that the batter will swing and miss.