Editing Speed skating (section)

===North American professionals===
During the 20th century, [[roller skating]] also developed as a competitive sport. Roller-skating races were professional from an early stage.<ref>Turner, James, in collaboration with Zaidman, Michael (1997). The History of Roller Skating. National Museum of Roller Skating. {{ISBN|0-9658192-0-5}}.</ref> Professional World Championships were arranged in North America between the competitors on that circuit.<ref>[http://www.hickoksports.com/history/rollerskate03.shtml Roller Skating 3: Types of Competition] {{webarchive|url=https://archive.today/20120905220659/http://www.hickoksports.com/history/rollerskate03.shtml |date=5 September 2012 }}, from hickoksprots.com. Retrieved 25 December 2006.</ref> Later, [[roller derby]] leagues appeared, a professional contact sport that originally was a form of racing. [[International Roller Sports Federation|FIRS]] World Championships of inline speed skating go back to the 1980s,<ref>[http://www.hickoksports.com/history/wminline.shtml World In-Line Skating Medalists – Men] {{webarchive|url=https://archive.today/20120903143310/http://www.hickoksports.com/history/wminline.shtml |date=3 September 2012 }}</ref> but many world champions, such as [[Derek Parra]] and [[Chad Hedrick]], have switched to ice in order to win Olympic medals.

Like roller skating, ice speed skating was also professional in North America. [[Oscar Mathisen]], five-time ISU world champion and three-time European champion, renounced his amateur status in 1916 and travelled to America, where he won many races but was beaten by [[Bobby McLean]] of [[Chicago]], four-time American champion,<ref>[http://www.encyclopedia.chicagohistory.org/pages/1146.html Ice Skating], The Electronic Encyclopedia of Chicago</ref> in one of the races. Chicago was a centre of ice speed skating in America; the ''[[Chicago Tribune]]'' sponsored a competition called the Silver Skates from 1912 to 2014.