<p>The inevitable has arrived. The United States and Canada will meet for gold Thursday (11:10 p.m. ET Wednesday, NBC) for the sixth time in seven women's hockey tournaments at the Winter Olympics. The U.S. is looking to defend its gold from four years ago but Canada is coming off a win in their preliminary round meeting. </p><p></p><p>Meanwhile, Kamila Valieva, the 15-year-old Russian whose presence in this event is the source of controversy after last week's revelation of a positive test for a banned substance in December, leads heading into Thursday's long program (5 a.m. ET, USA). The three Americans in the field are well off the medal pace after the first of the two-event competition Alysa Liu sits in eighth, with Mariah Bell 11th and Karen Chen 13th. </p><p></p><p>This is the last shot at a medal for Mikaela Shiffrin, who clocked the fastest time in the downhill training session among the 14 skiers