APBRmetrics

Charles · Joined: 16 May 2005 Posts: 134

The NBA is a very high profile business, so protecting the integrity of its product is paramount. It is clearly in the league's own best interest to be seen as 100% impartial. However, the league also has an undeniable interest in maximizing media coverage and viewership. So, given the recent statements from Tim Donaghy, some subtle bias in favor of large market teams is a legitimate concern.

As a quick and dirty test, I looked at each playoff game over the past twelve seasons and took the difference between a team's regular season point differential and their opponent's point differential. I adjusted for home court advantage. Then I compared the game result to the "expected" result.

For example, suppose San Antonio is visiting Utah and the Spurs have a regular season point differential of +7.2 while the Jazz have a regular season differential of +1.2. The Spurs are expected to win by six points. However, since the Spurs are on the road we subtract 4.2 from their advantage for a final spread of +1.8. If San Antonio wins the game by four points then they performed +2.2 better than expected. We do that calculation for each of the Spurs 133 playoff games and get an average difference of +0.4 (within the expected range.)

Brian M · Joined: 25 Nov 2006 Posts: 40

I don't know how much it affects the data, but in 1999 the Knicks were objectively much better in the playoffs than in the regular season. They underwent a significant overhaul by bringing in Camby and Sprewell, there were only 50 or so games for the team to gel due to the lockout, and Van Gundy didn't really begin trusting the new guys until late in the season. One might legitimately question Larry Johnson's 4 point play, but on the whole I'd expect the Knicks to look much better statistically in those playoffs than they did in the regular season, and not because of a refereeing bias.

Mountain · Joined: 13 Mar 2007 Posts: 1527

This is a timely start of a study.

I'd be interested in

1) how much of the big market edge was coming in home vs road games,

2) if there is a strong correlation of "unexplained playoff advantage" with free throw differential or FT/FGA game by game for the large market teams,

3) if there is a strong correlation of "unexplained playoff advantage" with opponent market size, and

4) what the regular season differential was between each playoff match-up and how much "unexplained playoff advantage" there is compared to that.

Referee bias is just one possible explanation. I wonder how much big market total team salary, or ability to attract free agents major and minor and retain players, or good fortune with or ability to pay / retain the best coaches and GMs may contribute to it as well.

A 12 year study is a decent length but does a 20+ year study show something similar. less or more pronounced?
If you split between pre and post modern salary cap system
what is the direction of the advantage?

Ryan J. Parker · Joined: 23 Mar 2007 Posts: 711 Location: Raleigh, NC

Help us understand what we're talking about here... What are the odds a +2.4 or +2.2 differential happens by random chance? Just how unlikely is this, assuming everything else being equal?

Charles · Joined: 16 May 2005 Posts: 134

Charles · Joined: 16 May 2005 Posts: 134

Charles · Joined: 16 May 2005 Posts: 134

Mountain · Joined: 13 Mar 2007 Posts: 1527

The Bulls large market contributed to Jordan's superstar call and no-call patterns as it did for others. It helped support his very expensive salary in the last part of his run there- #1 on team salary in the league the final 2 years.

New York being big stage New York definitely played a role in attracting Riley (at top dollar) and brought with him Jeff VanGundy. (putting aside the Ewing draft issue). And for the 2 years that ended in appearances in Finals they were #1 and #2 on total team salary. Supported by a big market.

Big market LA and the big check there helped bring Phil Jackson and Shaq (and Charlotte's market size influenced Kobe's draft day posture). Total team salary was 4th, 6th and 12th in the 3peat years. And recently made luxury tax Gasol more feasible than for other teams.

And if the big revenue streams bought a more expensive set of quality players and coaches I am not that surprised that the highest expression of that quality comes out in the playoffs... after the playing of the 82 game prelude. Of course not every big market team got max advantage via spending related influences but it is part of the picture.

The fact that the very biggest markets show the biggest playoff performance gains is notable and does raise the question if market size / "importance" played some role as well.

By referee impact .... or maybe some boost from fan support, team swagger & intimidation? Plenty of factors contributing or arguably contributing.

sptsjunkie · Joined: 17 Feb 2008 Posts: 16 Location: Los Angeles

As a Kings fan, I would love to believe it was all of the evil refs. However, another factor that probably inflates at least LA and Houston having higher than expected post-season results is that both of those teams were notorious for starting off the season slowly and saving energy and then getting in a rhythm and peaking right as the playoffs approached.

Is there a simialr correlation if you look at how teams performed in the final 1/3 of the regular season and the playoffs?