Top six teams advance to the playoffs (it should probably have been top eight in an 18 team league, but I didn't notice that until it was too late).
First and second seed get a bye while 3 plays 6 and 4 plays 5. Winners advance to the semi-finals and then the final matchup is the last week and a half of the season where I (err... or somebody) will win it all. Playoff matchups are the same as the weekly regular season matchups as far as rules and stuff go, except that there is a tiebreaker to determine the winner if it ends up 4-4-1.