NFL Winning Margins By Era

This is somewhat of a continuation from my earlier post today regarding the key numbers in NFL betting, and the findings of this Odds Shark post which opened with:

That’s because three is, by far, the most popular margin of victory in the NFL as far back as our OddsShark data goes (1984). A total of 13.95 percent of games are decided by three points in the NFL while 8.05 percent of games are decided by seven points, which is the second most common game differential.

Three point wins are indeed by far the most frequent margin of victory going back to 1989, with 15.5% of the 7,074 matches finishing that way. Seven points is second at 8.8% followed by ten points with 5.9%.

The top dozen margins (1989-2016) are :

The problem with all encompassing results like this is that all seasons are not the same. I mentioned the rule change prior to the 2015 season which resulted in fewer extra points being scored, and in 1994, the NFL adopted College Football's two-point conversion, both changes which should impact winning margins. 

Thus there are really three distinct periods for NFL margin data, pre-1994, 1994 to 2014, and 2015 to date (although this is likely sooner rather than later as further changes are already being discussed). 

Rugby is similar, in that when I played, a try was worth a measly three points, with a conversion worth two. I'm not old enough (quite) to remember when the try itself was worth no points, but at one time this was the case, before it slowly increased to its current five in 1992. 

Back to the topic, and here are the NFL's winning margins by 'era':

There are some notable differences, for example the increase in not only 5 point, 6 point and 8 point wins, but also in 7 point wins. 10 point margins are declining, as are 4 point and 17 point wins.

Of course other factors impact the winning margin, with greater parity in the league a major one, but it's always interesting to track these things.

Returning to Rugby, and a nice segue into the sad news for readers that this blog shall again be dormant for a while as I shall be away for a few days, taking a trip to see the Newcastle Falcons v Saracens game next Saturday in Philadelphia. I'll be one of the Bath Rugby shirt wearers, my son being the other.