The wound is still fresh from the United States' overtime loss to Canada in the 2010 men's ice hockey gold medal game in Vancouver, but the rivalry between the neighboring countries has plenty of other reasons for its intensity. Take for example, the women's soccer semifinal in the 2012 London Games that took two periods of extra-time to settle. Or the women's hockey final in Vancouver that saw the Canadians finish atop the podium. And let's not forget Thursday's gold medal game between the countries' women's hockey squads, an instant classic that needed overtime to crown a champion. All of these heated contests have occurred over the past four years and they set the stage for Friday's heavyweight, semifinal matchup between the Canadian and American men's hockey teams.