Multi-purpose Stadium - Field Layout

Field Layout

Most multi-purpose stadiums that existed in North America overlaid one sideline of the football field along one of the baseball foul lines, with one corner of the football field being located where home plate would be. Because the length of a regulation American football field is 360 feet, longer than the approximately 330-foot average for Major League Baseball, this requires an unusually long distance from the home plate to the fence along the foul line on which the football field is constructed, part of the football field to be constructed in foul territory (and the size of said territory to be increased accordingly), or a temporary wall. O.co Coliseum uses a configuration such that its football sideline runs along a line drawn from first base to third base (the former Atlanta-Fulton County Stadium also used this configuration). This was done presumably to make the same coveted seats behind home plate at a baseball game also coveted 50-yard line seats at a football game, and also so that the stadium would need only one press box. Different stadiums have different angles between the left and right field seats.

In stadiums that were primarily football stadiums that converted to baseball stadiums, the stands were at nearly right angles. This allowed the football field to be squared within the bleachers, but left the baseball configuration with many undesirable views farther away from home plate or facing away from the diamond, such as at the Kingdome, the Hubert H. Humphrey Metrodome and Sun Life Stadium. For stadiums such as the Los Angeles Memorial Coliseum, this also had the undesirable effect of having implausibly short foul lines, making it unacceptably easy to hit home runs. Baseball stadiums that converted to football stadiums had more of an obtuse angle between the stands. This made the football viewing farther away, and in some cases partially obscured as in Candlestick Park.

In the case of Qualcomm Stadium, the stadium was constructed with half of the Field-level seating permanent (built of concrete, in the southern quadrant of the stadium), and the other half portable (modular construction using aluminum or steel framing). When the stadium was configured for baseball, the portable sections would be placed in the western quadrant of the stadium and serve as the third-base half of the infield. In the football configuration, these are placed in the northern quadrant of the stadium (covering what is used as left field in the baseball configuration) to allow for the football field to be laid out east-west. This had the advantage of improving sightlines for both sports while keeping the baseball dimensions roughly symmetrical.