NEW OLEANS, La.—A rite of December in the NFL, along with Christmas, Hanukkah and meaningless games for the Jets, Bengals and Lions, is the release of playoff scenarios. Those scenarios become less complicated as the league gets deeper into the month. Suffice to note that eight of the top teams can clinch something this weekend. The real spotlight, of course, is on two of the clubs already headed to the playoffs: defending Super Bowl champion Kansas City at New Orleans.