Aside from the normal risks associated with athletic activities, a baseball outfielder has the added danger of the outfield fence looming behind him. While benign in and of itself, the outfield fence is also an obstacle that the outfielder may collide with while tracking down a fly ball. Therefore, architects began building ballparks with the warning track included in the design. The warning track is a section of dirt that runs parallel to the outfield fence and acts as a warning to outfielders that they are approaching the outfield wall.

The warning track was first officially introduced in Yankee Stadium. The dirt track that ran the entire perimeter of the baseball field was originally intended to serve as a running track for events other than baseball. Because of its position in the outfield, players began to realize that once they hit the dirt track, they were approaching the outfield wall. The warning track was born and began to be included in all baseball parks throughout the major leagues. The warning track now appears on just about all baseball fields, professional or otherwise.

In many ballparks, the warning track runs the perimeter of the field, just like in Yankee Stadium. This means that the track runs behind home plate, past the dugouts, and into the outfield parallel to the baselines and foul lines. However, only the outfield portion of the dirt track is called the warning track, as the outfielders are most likely to encounter the wall at the farthest reaches of the outfield. Once the outfielder runs onto the dirt farthest from home plate, he knows he has reached the warning track and is therefore running out of room in which to catch the fly ball.

The proximity of the warning track to the outfield wall also allows the outfielder to time a jumping catch. Many outfielders will track a fly ball by looking over his shoulder, and therefore will not see the wall fast approaching. Therefore, they will use the fringe of the warning track as an indicator that they can jump off the wall to pivot higher and rob a batter of a home run. The warning track frees up the outfielder’s field of vision to track a fly ball rather than having to look and see if he is going to collide with the wall.