Weighted On-Base Average (wOBA) is an offensive statistic developed by Tom Tango that uses linear weight formulas to calculate a player’s offensive contributions.
When calculating batting average, a single is valued equally to a home run. With on-base percentage, a walk and a triple both contribute the same amount of OBP points. wOBA elimates these flaws and ensures that every hit is valued equally by using the linear weight values.
wOBA has become the most accurate offensive statistic because it weighs outcomes at the plate based on how many runs that player’s team can expect to score as a result.
Because wOBA is scaled to match OBP: .310 or below is bad, anything around .340 is good, and anything above .380 is outstanding. League average normally hovers around .325.
Formula: wOBA = (.72*NIBB + .75*HBP + .9*S + .92*ROE + 1.24*D + 1.56*T + 1.95*HR + .25*SB – .5*CS)/PA