The GreenStalk

So, after looking at how sports teams’ records impact their odds of winning, I wanted to use that same approach to answer a couple more questions about sports.

Did free agency change the NFL? 

When the NFL instituted modern free agency between 1987 and 1992, the parity in the NFL increased, making good teams less dominant and upsets more likely.  This can be seen in the chart below, where the higher red curve indicates fewer upsets before free agency:

Do teams “turn it on” in the playoffs?

In the playoffs, good teams are more dominant.  Or, in other words, they are trying harder than they do in the regular season.  We can see this in the NBA:

And the NHL:

While it isn’t necessarily surprising to see the trends in the above charts, they do sort of prove that teams sometimes mail it in during the regular season.

(Note: I didn’t do this for baseball or football, as they don’t have enough playoff games to run the above analysis.)