First base

First base, or 1B, is the first of four stations on a baseball diamond which must be touched in succession by a baserunner in order to score a run for that player's team. A first baseman is the player on the team playing defense who fields the area nearest first base, and is responsible for the majority of plays made at that base.

In the numbering system used to record defensive plays, the first baseman is assigned the number 3.

Also called first sacker or cornerman, the first baseman is ideally a tall player who throws left-handed and possesses good flexibility and quick reflexes. Flexibility is needed because the first baseman receives throws from the other infielders, the catcher and the pitcher after they have fielded ground balls. In order for the runner to be called out, the first baseman must be able to stretch towards the throw and catch it before the runner reaches first base. First base is often referred to as "the other hot corner"—the "hot corner" being third base—and therefore, like the third baseman, he must have quick reflexes to field the hardest hit balls down the foul line, mainly by left-handed pull hitters and right-handed hitters hitting to the opposite field. They usually are power hitters that are in the top of the league in Home Runs and extra base hits while maintaining a .270 plus batting average.

Good defensive first basemen, according to Bill James, are capable of playing off first base so that they can field ground balls hit to the fair side of first base. The first baseman then relies upon the pitcher to cover first base to receive the ball to complete the out. Indications of a good defensive first baseman include a large number of assists and a low number of throwing errors by other infielders.

The nature of play at first base often requires first basemen to stay close to the bag to hold runners or to reach the bag before the batter. First basemen are not typically expected to have the range required of a third baseman, shortstop, second baseman or an outfielder. As a result, first base is not usually perceived to be as physically demanding as other positions. However, it can also be a very hard position to play; a large amount of concentration and timing is required. Though many play at first base their entire career, it is common for veteran players to be moved to first base in order to extend their careers or to accommodate other recently acquired players. Facing a possible trade or a considerable reduction in playing time, a player will usually opt to move to first base instead. Catchers and corner outfielders are often moved to first base due to deteriorating health or if their fielding abilities at their original position are detrimental to the team.

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Wikipedia