Rata, a skater of Barcelona’s Steel Groin roller derby team, skates during a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Rata (2nd R), a skater of Barcelona’s Steel Groin roller derby team, skates during a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Marinaker, a skater of Barcelona’s Steel Groin roller derby team, skates during a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

A view of tattoos on the leg of a skater of Barcelona’s Steel Groin roller derby team as the skaters stand during a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Rata, a skater of Barcelona’s Steel Groin roller derby team, jumps during a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Skaters of Barcelona’s Steel Groin roller derby team prepare for a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

A view of a bottle of water with a rainbow coloured wrist band wound around it, next to skaters of Barcelona’s Steel Groin roller derby team as they prepare for a training session, in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Referees talk in front of skaters of Barcelona’s Steel Groin roller derby team as they prepare for a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Skaters of Barcelona’s Steel Groin roller derby team talk during a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Skaters of Barcelona’s Steel Groin roller derby team participate in a training session in Barcelona, Spain November 16, 2022. REUTERS/Nacho Doce 

Women in roller derby outfits skate by with national flags during Fourth of July Independence Day celebrations in Washington, D.C., U.S., July 4, 2019. REUTERS/Tom Brenner 

Members of the Bad Fish roller derby team give high-fives to people gathered to watch a parade and celebrate at the Long Beach Lesbian and Gay Pride festival in Long Beach, California on Sunday, May 21, 2017. REUTERS/Andrew Cullen 

Nobel Laureates Rich Roberts (L) Dudley Herschbach (2nd L) and Eric Maskin play "Tick-Tock-Toe" against a roller derby team (R) during the 26th First Annual Ig Nobel Prize ceremony at Harvard University in Cambridge, Massachusetts, U.S. September 22, 2016. REUTERS/Brian Snyder

From L-R: France's Jean Frederic Chapuis competes with compatriots Arnaud Bovolenta and Jonathan Midol and Canada's Brady Leman during the men's freestyle skiing skicross finals round at the 2014 Sochi Winter Olympic Games in Rosa Khutor February 20, 2014. Chapuis won freestyle skiing cross gold to lead a stunning French podium sweep in the "roller derby on snow" at the Sochi Olympics on Thursday REUTERS/Dominic Ebenbichler (RUSSIA - Tags: SPORT SKIING OLYMPICS)

From L-R: France's Jean Frederic Chapuis competes with compatriots Arnaud Bovolenta and Jonathan Midol and Canada's Brady Leman during the men's freestyle skiing skicross finals round at the 2014 Sochi Winter Olympic Games in Rosa Khutor February 20, 2014. Chapuis won freestyle skiing cross gold to lead a stunning French podium sweep in the "roller derby on snow" at the Sochi Olympics on Thursday. REUTERS/Dominic Ebenbichler (RUSSIA - Tags: SPORT SKIING OLYMPICS TPX IMAGES OF THE DAY)

A player known as "Justine TimberSkate" is mobbed by fans in the closing moments of the Terminal City Rollergirls league championship game in Vancouver, British Columbia September 7, 2013. TimberSkate and her teammates, known as the Riot Girls, won the 2013 championship. REUTERS/Andy Clark (CANADA - Tags: SPORT SOCIETY TPX IMAGES OF THE DAY) 

Roller Derby referees, with their competition names on their backs, wait for the start of the Terminal City Rollergirls season championship game in Vancouver, British Columbia September 7, 2013. Within the league they are referred to as "Authority Figures" rather than referees. REUTERS/Andy Clark (CANADA - Tags: SPORT SOCIETY) 

Skaters from the Junior Arizona Derby Dolls warm up at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

A skater called "Lil Bruiser" from the Junior Arizona Derby Dolls waits to compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Skaters from the Junior Arizona Derby Dolls prepare to compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Skaters from the Junior Arizona Derby Dolls wait to compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Skaters from the Junior Arizona Derby Dolls wait to compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Zoa Benton (L), 17, is hugged by her mother, Shawn Ziegler, after competing at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Junior skaters from the Oxnard Sugartown Sugar Babies prepare to compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Sierra Olea, 12, of the Sugartown Sugar Babies from Oxnard, warms up at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Raquel Bell, 27, of the Sugartown Roller Derby in Oxnard sits with her equipment at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Natasha Tunaitis, 31, of the Penn Jersey Roller Derby from Philadelphia, displays a roller derby tattoo at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Emily Stockman, 31, from Seattle, applies make-up before the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Junior skaters from the Arizona Derby Dames and the LA Derby Dolls compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SPORT SOCIETY) 

Junior skaters from the Arizona Derby Dames and the LA Derby Dolls compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Junior skaters from the Arizona Derby Dames and the LA Derby Dolls compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Junior skaters from the Arizona Derby Dames and the LA Derby Dolls compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Skaters from the Junior LA Derby Dolls take a timeout at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Junior skaters from the Arizona Derby Dames and the LA Derby Dolls compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Junior skaters from the Arizona Derby Dames and the LA Derby Dolls compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Keylee Rosa, 3, looks at a mannequin at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Skaters compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Junior skaters from the Tilted Thunder Peeps and the Sugartown Roller Derby compete at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Relatives of junior skaters cheer them on at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Girls reach out to congratulate a winning team at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

A skater's relative holds up a sign at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Sierra Olea (R), 12, and Norelyn Herrera, 8, from Oxnard, warm up at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

A girl has her helmet adjusted before competing at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

SpongeBob SquarePants tape is seen on the toe of a skate at the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

Juniors participate in the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT) 

A member of the Penn Jersey roller derby team from Philadelphia talks on the phone outside the National Championship for Banked Track Roller Derby in Los Angeles, California, June 7, 2013. Roller derby is a real, full-contact sport, played at fast pace by all-volunteer teams on a banked oval track and was created in 1935 by Leo Seltzer in Chicago. Juniors are aged 7-16 and play on teams of ability, not age, and have feisty skater names such as Lil Bruiser, Ripper N Half, and Felony Melanie. Picture taken June 7, 2013. REUTERS/Lucy Nicholson (UNITED STATES - Tags: SOCIETY SPORT TPX IMAGES OF THE DAY) 

Members of the Terminal City Allstars (red) and the London Rollergirls compete in an international friendly roller derby game in Richmond, British Columbia June 1, 2013. The British team are currently on a tour of Canada and the U.S. playing teams from various local city leagues. Picture taken June 1. REUTERS/Andy Clark (CANADA - Tags: SPORT SOCIETY) 

Science fiction enthusiasts Deadly Dexito, real name Lydia Scott (L), Demolition Darcy, real name Heather Spence and Queen Mob who did not wish to give her real name, dressed as characters from the 1975 roller derby film "Rollerball," pose for a photograph outside the 12th annual Sci-Fi London festival in east London April 28, 2013. The international festival of science fiction and fantasy film runs from April 30-May 6. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY SCIENCE TECHNOLOGY) 

Science fiction enthusiasts Deadly Dexito, real name Lydia Scott (L), Demolition Darcy, real name Heather Spence and Queen Mob who did not wish to give her real name, dressed as characters from the 1975 roller derby film "Rollerball," pose for a photograph outside the 12th annual Sci-Fi London festival in east London April 28, 2013. The international festival of science fiction and fantasy film runs from April 30-May 6. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY SCIENCE TECHNOLOGY) 

The Faster Pussycats' NazDroveya Wylde (L) elbows the Bad Reputations' Major Assets (C) during the Terminal City Rollergirls League championship roller derby game in Vancouver, British Columbia September 8, 2012. The women's roller derby league was created in 2006 and the Faster Pussycats won this year's championship. Picture taken September 8, 2012. REUTERS/Andy Clark (CANADA - Tags: SPORT) 

Members of the Faster Pussycats and Bad Reputations jockey for position during the Terminal City Rollergirls League championship roller derby game in Vancouver, British Columbia September 8, 2012. The women's roller derby league was created in 2006 and the Faster Pussycats won this year's championship. Picture taken September 8, 2012. REUTERS/Andy Clark (CANADA - Tags: SPORT) 

Members of the Faster Pussycats celebrate their victory following the Terminal City Rollergirls League championship roller derby game in Vancouver, British Columbia September 8, 2012. Created in 2006 this is the first roller derby league for women in the city. Picture taken September 8, 2012. REUTERS/Andy Clark (CANADA - Tags: SPORT) 

The Faster Pussycats' Evada Peron (L) and Ryder Gentley celebrate their victory during the Terminal City Rollergirls League championship roller derby game in Vancouver, British Columbia September 8, 2012. Created in 2006 this is the first roller derby league for women in the city. Picture taken September 8, 2012. REUTERS/Andy Clark (CANADA - Tags: SPORT) 

A skater from the Stockholm Roller Derby sports a tattoo of a roller derby skater on her leg as she listens to her coach during a practice session in Huddinge June 9, 2011. Flat track roller derby consists of two teams of five players each and points are scored when the assigned scorer or "jammer" laps member of the opposing team. Picture taken June 9, 2011. REUTERS/Bob Strong (SWEDEN - Tags: SPORT SOCIETY) 

Skater "Cherry D'vine" from the Stockholm Roller Derby shows the tattoos on her hands before a women's flat track roller derby bout against the Kallio Rolling Rainbow in Huddinge June 11, 2011. Flat track roller derby consists of two teams of five players each and points are scored when the assigned scorer or "jammer" laps member of the opposing team. REUTERS/Bob Strong (SWEDEN - Tags: SPORT SOCIETY) 

Skaters from the Stockholm Roller Derby listen to their coach "Sloppy Boggins" as they work out before a women's flat track roller derby bout against the Kallio Rolling Rainbow in Huddinge June 9, 2011. Flat track roller derby consists of two teams of five players each and points are scored when the assigned scorer or "jammer" laps member of the opposing team. Picture taken June 9, 2011. REUTERS/Bob Strong (SWEDEN - Tags: SPORT SOCIETY) 

Skater "Milky Madness" of the Stockholm Roller Derby listens to her coach during a practice session before their women's flat track roller derby bout against the Kallio Rolling Rainbow in Huddinge June 9, 2011. Flat track roller derby consists of two teams of five players each and points are scored when the assigned scorer or "jammer" laps member of the opposing team. Picture taken June 9, 2011. REUTERS/Bob Strong (SWEDEN - Tags: SPORT SOCIETY) 

A sign points to the "Suicide Seats", due to their location on the floor next to the track, during a women's flat track roller derby bout between the Stockholm Roller Derby and the Kallio Rolling Rainbow in Huddinge June 11, 2011. Flat track roller derby consists of two teams of five players each and points are scored when the assigned scorer or "jammer" laps member of the opposing team. REUTERS/Bob Strong (SWEDEN - Tags: SPORT SOCIETY)