Isolated Power
From Wiki
Isolated Power is a simple measure of a player's power, invented by Branch Rickey and Slugging Average minus Batting Average.
Isolated Power is considered a truer measure of power than Slugging Average because the latter includes bases gained on singles. Subtracting Batting Average serves to remove the first base of every hit from consideration.
Isolated Power = (D + 2*T + 3*HR)/AB = (TB - H)/AB = SLG - BA
