HOME MEET CRRG BOUT SCHEDULE/TICKET INFO JOIN CRRG CRRG BOOSTER PROGRAM ROLLER DERBY 101 SPONSORS COMMUNITY INVOLVEMENT CRRG IN ACTION! (PHOTOS) CRRG VIDEOS CONTACT US WFTDA Roller Derby 101: A Crash Course A Roller Derby team is organized into squads who take turns playing. Each game is called a bout, played in two 30 minute halves consisting of segments called jams that last up to 2 minutes in length and keep the action going. Within each team, the squads consists of: four blockers (with one as an optional pivot) and one jammer, who is only player to score points. "The pack" is a combination of blockers from both teams within certain distance of each other. Offense and defense are played at the same time by both teams simultaneously. The jam begins when the ref blows one short whistle.