For the Seattle Sounders to defend their MLS Cup they must beat the first team to eject them from the MLS Cup Playoffs. In 2009 it was the Houston Dynamo who were the mighty powers, recently with two MLS Cups and favored. It took until extra time in the second leg for the Dynamo to beat the upstart Sounders.
In 2017 Seattle is the favorite. They are the reigning champions, the higher seed and the statistics sites see them as better (538, Sagarin, ASA). Four-seed Houston beat five-seed Sporting KC 1-nil and one-seed Portland 2-1 to make the Western Conference Finals.