Covering a base

In baseball, part of the infielders' and pitcher's jobs is to cover bases. That is, they stand next to a base in anticipation of receiving the ball thrown from another fielder, so that they may make a play on an opposing baserunner who is approaching that base. On a force play or appeal play, the fielder covering the base stands with one foot on that base.

In general, the first baseman covers first base, the second baseman or shortstop covers second, the third baseman covers third, and the catcher covers home plate. However, on ground balls hit to the first baseman away from first base, the pitcher will cover first base instead. On a ground ball to either the shortstop or the second baseman, the other of those will cover second base.

With a runner on first base, when a ground ball is hit to the third baseman, second base will be covered by the second baseman, because unlike the shortstop he does not have to turn his back to the third baseman in order to get to second base. Likewise, with a runner on first base, when a ground ball is hit to the first baseman, second base will be covered by the shortstop, who unlike the second baseman does not have to turn his back toward the first baseman in order to get to second base.

When a runner on first base attempts to steal second base, the shortstop and second baseman will have arranged in advance which one will cover second base to receive the ball from the catcher. Likewise, when the pitcher attempts to pick off a runner at second base, the shortstop and second baseman will have arranged in advance which one will cover second base.

With baserunners on first and second bases, sometimes the shortstop will cover third base on a bunt, a coverage plan known as the "rotation play" or "wheelplay." This occurs if the batter bunts the ball toward third base so that the third baseman cannot cover third base because he is moving forward to field the ball.

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