We round out the calculations by giving some weight to championship droughts (17 years for Atlanta, 33 years for Seattle) and to the ratio of total seasons to championships won (for example, the four teams in Phoenix sports history have competed for a combined 95 seasons with one title to show for them, courtesy of the 2001 Diamondbacks).
We scored each city on the number of times one of its teams has lost in the postseason, adjusting the misery points to give the most weight to losing in the final round (World Series, Super Bowl, NBA Final, Stanley Cup Final) and doling out progressively fewer points for losing earlier playoff rounds.