"Princess Slay-Ya" of the Kansas City Roller Warriors (L) trips up Denver Roller Dolls "Angela Death" in their roller derby bout in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Fawn Stalking" of the Denver Roller Dolls stretches for their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Fawn Stalking" of the Denver Roller Dolls stretches for their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Friction Vixxen" of the Denver Roller Dolls stretches for their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

Members of the Denver Roller Dolls (on the ground) tangle in their roller derby bout against the Kansas City Roller Warriors (in red) in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Diamond Lil" of the Denver Roller Dolls stretches for their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

Fans of the Denver Roller Dolls cheer at their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Primal Rage" (L) and "Ivona Killeau" (R) of the Denver Roller Dolls wait in the penalty box during their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

A member of the Denver Roller Dolls has her skates tuned up for their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Ivona Killeau" of the Denver Roller Dolls stretches for their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Jail Bait" a referee of the Denver Roller Dolls prepares for a roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

The Denver Roller Dolls talk before their roller derby bout against the Kansas City Roller Warriors in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES) 

"Annie Maul" of the Kansas City Roller Warriors prepares for their roller derby bout against the Denver Roller Dolls in Denver, Colorado March 9, 2007. The women's roller derby takes place on a flat track before thousands of avid fans. REUTERS/Rick Wilking (UNITED STATES)