11 of the last 15 champions (73%) had a quarterback with a passer rating ranked in the top 10.
So do defenses win championships? Yes, but it is not the only way. My recommendation would be for teams to concentrate on getting either the offense and/or the defense into the top 10 ranking. Only 3 of the past 15 champions (20%) ranked out of the top 10 in both offense and defense.
After taking a quick peek at where my team, the Philadelphia Eagles (the color choices in the app make sense now :), ranked this year (OFF Rnk =16th, DEF Rnk=27th and PR Rnk=26th), it seems that my boys have areas to address on both sides of the ball before we can think about parading down Broad Street.
Hopefully for you, your team is further along in the process.
Here is a detailed view of the last 15 champions: