OBP (On Base Percentage):
Purpose: To determine how often a player reaches base, either by hit, walk, or hit by pitch.
Introduced: 1984
Explained: Assuming that a player has received a sufficient number of plate appearances, the differential between his batting average and OBP will often tell how patient that hitter is. In 2004, Barry Bonds's OBP was .609, while his batting average was .362, an indication of his incredibly high walk total of 232.
OBP=(Hits+Walks+HBP)/Plate Appearances
