Marginal Lineup Value
Marginal Lineup Value (MLV) is a rate of offensive performance developed by David Tate. In its initial form, it was expressed in terms of runs created above average over a full season. MLV is used by Keith Woolner as the basis for offensive VORP.
MLV is based on the Runs Created model of offense (particularly that Runs = OBP*SLG*AB), and attempts to correct for the use of a dynamic run estimator to evaluate individual performance by placing a player on a theoretical team with eight average players. It is thereby similar to the theoretical team construct of Runs Created, but MLV goes a step further by estimating the number of plate appearances the new lineup will generate instead of assuming a constant number of PAs.
Calculation of MLV[edit]
To find MLV, one must first calculate the number of runs an average team of nine players will score:
T_PA = G*O/(1 - LgOBP)
T_AB = T_PA*(1 - LgOBP)/(1 - LgBA)
T_R = LgOBP*LgSLG*T_AB
where G = number of games (162 for the full season version) and O = outs/game (often held fixed at 25.5)
Then, given the assumption that the player in question will get 1/9 of the team PAs, his effect on the team can be measured:
TP_OBP = (8*LgOBP + OBP)/9
TP_PA = G*O/(1 - TP_OBP)
TP_PA_EACH = TP_PA/9
TP_AB_EACH = TP_PA_EACH*(1 - LgOBP)/(1 - LgBA)
TP_AB_HIS = TP_PA_EACH*(1 - OBP)/(1 - BA)
TP_AB = 8*TP_AB_EACH + TP_AB_HIS
TP_SLG = (8*LgSLG*TP_AB_EACH + SLG*TP_AB_HIS)/TP_AB
TP_R = TP_OBP*TP_SLG*TP_AB
MLV is simply TP_R - T_R.
Criticisms of MLV[edit]
MLV goes through a long series of steps in order to get to the impact of a player on his team. But, it starts off with the worst version of Runs Created to begin with. Improving the accuracy by a couple of runs by going through the Theoretical Team approach, but starting off with something very inaccurate to begin with doesn't necessarily leave you any better off than just going with a straight Linear Weights approach.
