THE BOOK--Playing The Percentages In Baseball

Did the author note how many games were in each conference rivalry?  Maybe we can get use some Bayesian method to get an estimate of the “true” disparity in talent.

In a thread last year, I noted the percentage of interconference games in each league.  It was something like 10% in MLB, 20% in NHL, NBA.  Can’t remember NFL, but it could have been around 20% as well.

I think if you click the “football” link above, you might be able to find the thread.

NFL teams play 4 interconference games (a complete series against one other division), so it’s 25%.

To expound on the NFL, the breakdown between conference/non-conference games used to be weirder.  Now there are eight 4-team divisions, and you play each team in one division from the other conference (4 games), each team in your division twice (6 games), leaving 6 games against non-division opponents from your conference.  This means you end up playing 10/15 = 67% of the teams in your conference, and 6/13 = 46% of non-division, intraconference teams.

For a few years, though, there were 31 teams, which created some strange stuff.  The AFC Central had six teams, meaning there were 10 intradivisional games.  That left just 6 games to be played between non-division and interconference foes, and so in 1999-2001, the Browns played 3 games versus the NFC and 3 versus the AFC East and West, plus the 10 divisional games.  So while the percentage of interconference games was lower, they were only facing 9/16 = 56% of the teams in the conference, and 3/10 = 30% of non-division, intraconference teams.