Thursday, January 31, 2008

The best team in NFL history

Both the 1972 Miami Dolphins and the 2007 New England Patriots were undefeated in the regular season. Dr. Jonathan Sackner-Bernstein, an admitted Dolphins fan, has looked at the question of which was the better team. Since, of course, they could never play each other, we can't know with certainty. But we can analyze the two teams statistically and interpret the results.

You can read the article at, but you'll need to go through the free registration process to get to the full text. I'll summarize what I understand here:

Sackner-Bernstein's analysis involves normalizing the data from the individual game results of both teams with data from their opposing teams. I believe the purpose here is to compare Miami and New England relative to how all the teams in the league are doing. In other words, when we look at points scored, if all teams are scoring more points in 2007 than in 1972 (for whatever reason), the normalization factor will scale down the New England number of points scored to be relative to the average points scored in 1972.

Another factor in the analysis is to assess the strength of both Miami and New England relative to the teams they faced. For example, if Miami beat their opponents by a wide margin and their opponents were all relatively good teams while New England beat their opponents by a thin margin and their opponents were relatively weak, we would conclude that Miami was the better team. In order to normalize for that factor, Sackner-Bernstein multiplies the statistics for each game by the season-end winning percentage of each opponent. For example, a 20-10 win over a team that had a winning percentage of .500 would count as 10-5, whereas a 27-21 win over a team that ended the season at .333, would count as 9-7.

The analysis also calculated stats on a game-by-game basis to determine if there was a trend in either team as performing better or worse over the course of the season.

Therefore, Sackner-Bernstein first gathered data on the outcomes of all the 14 Miami games and 16 New England games. Then he gathered data on all the other teams in the league. The four statistics that he gathered were:
1. points scored
2. points against
3. total yards offense
4. total yards defense
The points and yardage differentials were also considered.

You can see the tabulation of the results in the article. I'm interested in get hold of the mean values for the league and I've contacted Sackner-Bernstein's organization to try to obtain those data. They would make a great sample exercise. I'm also trying to understanding the p-value concept. I'll have to wait for chapter 9 (pg 286) to get into that.

Sackner-Bernstein concludes:

Thus, this analysis concludes that the regular season performances of the 1972 Miami Dolphins and the 2007 New England Patriots are statistically indistinguishable in terms of dominance over their opponents in each of their respective seasons. Under the assumption that the Patriots reign victorious in this year's Super Bowl, one can only conclude that the two teams are equally dominant and should be considered the two teams tied for the best single-season performances in the NFL's modern era.

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