In baseball, a baserunner is said to be left on base (abbreviated LOB) when the half-inning ends, he has not scored, and he has not been put out. This is to include a batter-runner who, say, has hit into a fielder's choice, causing another runner to be put out as the 3rd out; remember that when the batter hits a fair ball, his plate appearance ends and he becomes a runner. Team LOB totals are commonly reported in a baseball box score. Individual LOB statistics can also be tracked. A related statistic is Left On Base in Scoring Position, which includes only those LOB where the runner was occupying second or third base. Yet another related statistic is Left On Base in Scoring Position with Less Than Two Out. The intention of these statistics is to measure the tendency of a team or player to waste an opportunity to score. This article is about the sport. ... In baseball, baserunning is the act of running around the bases performed by members of the team at bat. ... In baseball, a run is scored when a player advances safely around all three bases and returns safely to home plate. ... In baseball, an out occurs when the defensive team effects any of a number of different events, and the umpire rules a batter or baserunner out. ... In baseball, the statistical summary of a game is reported in a box score. ...

LOB is used in "proving" a box score. The number of a team's plate appearances is to equal the sum of that team's runs, that team's LOB, and the opposing team's putouts. In other words, every batter who completes a plate appearance is accounted for by a run scored or by being put out or by being LOB.

"Stranded" is sometimes used to mean LOB.