The fourth game of a seven-game series always proves interesting: a team can win in a sweep, or take a decisive 3-1 lead that history has proven very difficult for the other team to come back from, or it can mean a clean slate with both teams at 2-2. A Blackhawks win provides the latter scenario. Sports contributor Cheryl Raye Stout breaks down the game, and helps explain the intricate rules surrounding the shifting of players on and off the ice known as “line changes.”(Flickr/howsmyliving)