Serena Williams is already among the best athletes of all time, so if she says she spots a winner, it's hard to ignore her. In an interview with Time magazine, Williams singled out former 49ers quarterback Colin Kaepernick as someone who could get a Super Bowl ring -- if he were given an opportunity. Kaepernick is in the midst of a collusion grievance against NFL owners, in which he says that there has been a concerted effort to keep him out of an NFL uniform due to his protest against racial equality by kneeling during the national anthem. The form...