Tennis polo
The sport is played on a grass field between 80 and 100 yards long and 50 to 65 yards wide. The goal area is a semicircular line with an 11-yard radius and the penalty mark at 13 yards from the goal. An experimental rule has a second semicircular line on the field with a 17-yard radius. Generally, a field for gridiron football or soccer can be used.
List of gridiron football rules
"Yard lines" cross the field every , and are numbered every 10 yards from each goal line to the 50-yard line, or midfield (similar to a typical rugby league field). Two rows of short lines, known as inbounds lines or "hash marks", run at 1-yard (91.4 cm) intervals perpendicular to the sidelines near the middle of the field. All plays start with the ball on or between the hash marks. Because of the arrangement of the lines, the field is occasionally referred to as a gridiron.