Baseball POP Glossary

  • Pitch Combos: 1-2 sequences of pitches defined by any difference in pitch type, X-Zone location change, or Z-Zone location change from the first to the second pitch. Example: Four-Seam Fastball followed by a Curve Ball that is 1 Zone higher in the Strike Zone and 2 Zone More Inside to the Hitter.
  • Pitch Combo Repertoire wOBA Added: Weighted average wOBA Added across all oberseved 1-2 Pitch Combos for a pitcher. Pitch Combos are weighted based on their usage rate relative to all other Pitcher Pitch Combos.
  • Pitch Combo Usage Rate: The % a single Pitch Combo is used relative to all other Pitch Combos.
  • Strike Zone X-Axis: Position of the pitch across the plate relative to the hitter. Zone 0is the inside edge of the strike zone, Zone 3 is the outside edge. This normalizes pitch locations for left- and right-handed hitters.
  • Strike Zone Z-Axis: Position of the pitch above the plate relative to the hitter. Zone 0is the bottom edge of the strike zone, Zone 3 is the top edge. This normalizes pitch locations for hitter height and relative top/bottom of their individual strike zones.
  • Whiff: Swing-and-miss by a hitter
  • wOBA Added: The change in expected wOBA outcome for the at-bat from pitch-to-pitch. This is a proxy for the relative value added by each individual pitch and how it changes the chances of success for the pitcher and hitter.