Rather than the bar charts from earlier I used Tableau to create pie charts showing the fraction of simulations in which a team wins the Superbowl as a function of the home advantage and the standard deviation of the normal distribution dividing the spread. (click the chart for larger).
Does this show better the expectation that New England would win assuming the straight Sagarin ratings determine the winner of each game? The stdev equal to 0.001 assumes that the favored team in the spread wins automatically. The fractions in the pie charts show how NE is dominant even using the normal distribution to more realistically represent teams' chances of winning. A stdev of 1000 is approaching the case where each game is 50/50. Notice the teams without a BYE are more likely to win the Superbowl in this case. That just because they play one fewer game and have one less chance to lose.
Players stats are entered and I am modifying the simulation to let me test 20 rosters at a time in 1000 simulations of the playoffs. More to come.