Last year, Denver had a pretty tough schedule. In only five games did they face an opponent that an average team would have been favored to win: ^[1]I.e., home games against teams with SRS ratings of 3.0 or worse, or road games against teams with SRS ratings of -3.0 or worse. home games against San Diego, Baltimore, and Oakland, and road games against the Colts and Browns. In those games, Denver went just 3-2, with all five games being decided by one score.

The Broncos had six games against top-8 teams by the SRS: two games against the Chiefs, and games against Cincinnati, Minnesota, New England, and Pittsburgh. In those games, Denver went even better at 4-2, with five of those games being decided by one score.

The middle five games of the schedule by SRS standards was where the Broncos really dominated: the Broncos went 5-0 in road games against Oakland, San Diego, Chicago, and Detroit, and a home game against Green Bay, with three of those five wins coming by double digits.

As it turns out, Denver had the third “strangest” season in the NFL last year. How did I define strange? I measured the correlation coefficient between two variables: the actual margin of victory in a game, and the opponent’s SOS (after adjusting for home field advantage). The Broncos had a CC of 0.18, which means (in case you couldn’t figure it out above) that there wasn’t a big relationship between results and expectation.

The Seahawks had the strangest season by this measure, though it may be a bit misleading. Seattle had a correlation coefficient of 0.10, but it was 0.34 if you remove the week 17 game where the Seahawks blew out the Cardinals in Arizona. That game is a bit tricky to analyze: it wasn’t a meaningless game for the Cardinals, but it wasn’t a totally meaningful one, either, and Arizona removed starters midway through the game. Given the large change in CC by removing that game, I thought it was worthwhile to point that out.

The Eagles had the second strangest season, with a CC of 0.17, and there’s no doubt that Philadelphia’s season was pretty weird (more on that tomorrow). The Eagles lost by 28 at home to Tampa Bay but also won in New England (one of just two games during the Brady era where New England lost at home to a team that finished with a .500 or worse record).

The least strange season? That honor goes to the Cleveland Browns, who had a correlation coefficient of 0.74 between expected and actual results. The table below shows how “strange” each team’s season was in 2015: