During the 2004 season, Barry Bonds reached base safely a total of 376 times, yet his official number of at-bat was only 373. He is the only player in the history of baseball to accomplish such a “reverse” feat.
While playing for the Giants that year, Bonds made a total of 617 plate appearances. He amassed 135 hits and 232 walks, was hit by a pitch 9 times, and had 3 sacrifice flies. Walks, times hit by a pitch, and sacrifice flies are deducted from a player's plate appearances to arrive at his at-bat total, hence the number 373. Correspondingly, walks and times hit by a pitch are added to hit to arrive at a players safely-reached base total, hence the number 376.
Expressed a different way, Bonds had a history-making on-base percentage (OBP) of .6094 in 2004, besting his own previous record of .5817 that he set in 2002. To make the feat even more amazing, Bonds turned 40 in 2004.