Baseball is played between two teams of nine players each on a baseball field,under the authority of one or more officials,called umpires.There are usually four umpires in major league games; up to six (and as few as one) may officiate depending on the league and the importance of the game.There are four bases.Numbered counter-clockwise,first,second and third bases are cushions (sometimes informally referred to as bags) shaped as 15 in (38 cm) squares which are raised a short distance above the ground; together with home plate,the fourth "base," they form a square with sides of 90 ft (27.4 m) called the diamond.Home base (plate) is a pentagonal rubber slab known as simply home.The field is divided into two main sections:
The infield,containing the four bases,is for defensive and offensive purposes bounded by the foul lines and the grass line (see figure).However,the infield technically consists of only the area within the bases,including the foul lines.
The outfield is the grassed area beyond the infield grass line (for general purposes; see above under infield),between the foul lines,and bounded by a wall or fence.Again,there is a technical difference; properly speaking,the outfield consists of all fair ground beyond the square of the infield and its bases.The area between the foul lines,including the foul lines (the foul lines are in fair territory),is fair territory,and the area outside the foul lines is foul territory.
The game is played in nine innings (although it can be played with fewer,such as it is in little league) in which each team gets one turn to bat and try to score runs while the other pitches and defends in the field.An inning is broken up into two halves in which the away team bats in the top (first) half,and the home team bats in the bottom (second) half.In baseball,the defense always has the ball — a fact that differentiates it from most other team sports.The teams switch every time the defending team gets three players of the batting team out.The winner is the team with the most runs after nine innings.If the home team is ahead after the top of the ninth,play does not continue into the bottom half.In the case of a tie,additional innings are played until one team comes out ahead at the end of an inning.If the home team takes the lead anytime during the bottom of the ninth or of any inning thereafter,play stops and the home team is declared the winner.