The referee calls the penalties and is responsible for awarding goals. The linesmen concentrate on offside and icing calls. In the waning minutes of a game, teams that trail by one or more goals may replace their goalie with another offensive player. The calculated risk could mean the difference in a game-tying goal. Of course, it could also mean a worse defeat as the open goal is more vulnerable.
Water is sprayed over a concrete floor imbedded with freezing pipes.
The playing surface is made of several layers. All markings on the hockey rink, including face off spots and encroachment lines, are painted after the ice is built to a half-inch thickness. Additional water is sprayed to cool the markings and build the ice to the prescribed thickness. The Stanley Cup is hockey's most coveted prize, named after Lord Stanley of Preston, Canada's Governor-general who donated a cup to the amateur hockey champs of his country in 1893. Today, the Stanley Cup is awarded annually to the NHL playoff champion.