Just about two weeks ago, I posted some data analyizing the rate of playoff games that went to overtime from 1970 to 2009. That data shows a marked increase in overtime playoff games since 1999. This post takes a look at the rate of tie and overtime games for the history of the league.
How the data was gathered
I used the data as given on pro-football-reference.com.
Only NFL games were considered. This means the first two APFA seasons, the AAFC and AFL games are not included in this data.
The number of teams in the league and number of games played each season has, of course, fluctuated. Therefore, the numbers for each season are presented as a percentage of games played, in order to make them as comparable as possible season-to-season.
The Data
Here is a graph of the result. The red line represents tie games, the blue line represents overtime games.
Comments:
There's a surprising amount of season-to-season variation, even in the modern era, of games that are tied after four quarters.
The rate of overtime playoff games from 1970 to 1998 (3.7%) is at the lower range of regular season overtime games during that era; the rate of overtime playoff games 1998 to 2009 (14.3%) is well over the rate of regular season overtime games.
There doesn't seem to be an increase in the number of overtime games in the regular season since 1999. Certainly nothing as dramatic as what has happened in the playoffs.
Interesting stuff I found while looking at the data:
The two highest-scoring tie games were both in the AFL: Raiders 43, Patriots 43 (1964), and Bills 38, Broncos 38 (1960). The highest-scoring tie games in the NFL is 35-35, which happened five times (so far), including once in the AFL.
The team with the most ties in a single season is the NFL Champion 1932 Chicago Bears, who posted a record of 7-1-6. No other team has more than 4 ties in a season, and no team has had more than 3 in a season since 1932.
