Manhattan —

For six days a week, the Hunter College Sportsplex is exactly what it sounds like: the gym for the school’s athletic department. But on Saturday night, mats are thrown down and the gym become home to the Gotham Girls Roller Derby league, whose members come to skate, block and jam at high speed.

Gotham Girls Roller Derby is a non-profit, all-women, do-it yourself league boasting four teams: the Bronx Gridlock, the Brooklyn Bombshells, the Manhattan Mayhem and the Queens of Pain. The League’s mission is to promote the physical and mental strength of its athletes.

Roller derby is played with five players per side. There are three blockers, a pivot and a jammer. The jammer starts out behind all of the rest of the players and tries to get past all of the opposing team. The blockers’ job is to make sure the jammer does not pass them. The jammer receives a point for every opposing team player overtaken before hitting the starting line again. The pivot calls the plays and directs traffic.

A game, or bout, is played over two 30-minute halves. Each bout is made up of many sets called jams.