Success is dependent upon teamwork, aggressive movement, and constant communication. Players wear uniforms, similar to more traditional sports. Speedball leagues specify the points system to be used for games. For example, in the NPPL's "opposing flag" format, points are awarded for staying in the game the whole round, shooting someone out, grabbing the flag, and hanging the flag. PSP uses the "Race2" format, where a match between two teams involves multiple games of "center flag"; there is a flag in the center of the field, and a team is awarded a point every time the flag is captured and hung on the opposing team's start box. Teams can play to a certain number of points, or to a set time limit. Because of the small size, generally less than 20,000 square feet, and openness of the field, proper positioning combined with restricting movement is a primary element of speedball tactics; the team who is better able to keep their opponents pinned behind cover while they themselves are free to move will have an enormous advantage. Therefore, the number of shots fired by each player is significantly higher than in woodsball games. There are a variety of paintball leagues that employ speedball as their format for tournaments. The main national league in the US is the PSP (Paintball Sports Promotions). The 7-man format run by the NPPL (National Professional Paintball League) has had numerous attempts to be a viable league but haven't had the stability to maintain a constant season. They're on hiatus but are planning on returning in 2015. The Millennium Series is Europe's national league and features rules and styles of game play similar to that of the PSP, NPPL and LAPPL. Sponsorships, television endorsements, extensive media coverage, and nationwide events have all pushed the leagues into mainstream popularity. In 2007, at World Cup, the most popular PSP event located at Disney’s Wide World of Sports Complex, boasted over 35,000 spectators and featured 373 teams. There are also numerous regional and local events all over the world, including most paintball fields which many times host their own events. Speedball paintball markers are designed to be small so they do not present a large target; in virtually all tournament rule sets, a player is eliminated if they, or anything they are wearing or holding including their marker, is hit. Tournaments also specify allowable firing modes and rates of fire. For instance, PSP league rules place a 10.2 (balls per second) limit or "cap" on rate of fire, but allow a marker to "ramp" (shoot additional shots per trigger pull) when the trigger is pulled rapidly.