In baseball, an at bat (AB) or time at bat is a batter's turn batting against a pitcher. An at bat is different from a plate appearance. A batter is credited with a plate appearance no matter what happens during his turn at bat. A batter is not credited with an at bat if he: At bats are used to calculate certain statistics, including batting average, on-base percentage, and slugging percentage. A player can only qualify for the season-ending rankings in these categories if he accumulates 502 plate appearances during the season.