There is a chance Seattle will have clinched a playoff berth before kicking off against the San Francisco 49ers in the Sunday night game. The most likely scenario for that to happen would be for Minnesota, Chicago and Washington to lose their games earlier in the day.
The chart shows all the ways Seattle can clinch a playoff berth Sunday if the Seahawks win or lose their game against the 49ers.
Several additional scenarios would come into play if the 49ers-Seahawks game ended in a tie. I've got those handy just in case.