Baseball has several categories of players to encompass more specific fielding positions, depending on where the players typically stand in the field. For example, outfielders include the left fielder, right fielder, and center fielder. The corners include first basemen and third basemen; and the positions of short stop and second base are known as middle infielders. The middle infielder positions work together closely when coordinating on double plays, and they must communicate with each other on ground balls up the middle – or, ground balls hit between their respective positions.

Playing a middle infielder position requires much athletic ability and agility. Because the middle infielder positions cover more ground than the corners, they must be physically fit and able to dive for balls when necessary. In addition, the second baseman and shortstop must maintain constant communication to determine who will receive a throw should the catcher choose to attempt to throw out a runner stealing second base. The middle infielder positions also adjust their defensive positions based on whether the batter is left-handed or right-handed, and the shortstop and second baseman must work with each other to make sure the middle of the infield is properly covered.

The most exciting aspect of the middle infielder positions is the double play. A double play occurs when a runner is occupying first base and the batter hits a ball to any of the infield positions. The infielders then coordinate to throw out both the runner heading toward second base and the batter running toward first base. The most common type of double play involves both middle infielder positions, as well as the first baseman, and is called a 6-4-3 double play, with the numbers indicating the player’s position on a score sheet. This type of play means the shortstop fields the ball, flips or throws it to the second baseman covering the base, who then throws the ball to first base to record the second out. This type of double play requires communication and agility on the part of both middle infielder positions.