MLV, or Marginal Lineup Value, is a statistic that measures a player’s offensive production in runs above an average offensive player. MLV takes a theoretical team of nine average hitters, replaces one of them with a player we want to measure, gives him the same percentage of the team’s total plate appearances (PA) as he had on his real team, and computes how many more (or fewer) runs the team would score as a result of the switch.
A positive MLV indicates that the player is an above-average hitter, and a negative MLV indicates the player is a below-average hitter. For example, a player with a 42.0 MLV means that the player would have produced 42 more runs for an average team than a league-average hitter would have had in the same amount of playing time. MLV is park-adjusted and calibrated to league average.