Comments on: Year-to-Year Four Factor Correlations

By: Bronn

Bronn — Tue, 20 Oct 2009 17:55:39 +0000

Sure it's odd for me to comment a month after the fact, but don't you find it more than a coincidence that 4 of the 5 top teams in opposition 3FG% were also the 4 best teams in the NBA last year? Seems to me that part of being a team that can win 60 games is solid perimeter defense-limiting your opponents' open looks. There's still going to be variance year to year, but it can't entirely be luck when the best teams end up at the top of the list.

By: Ryan J. Parker

Ryan J. Parker — Tue, 29 Sep 2009 17:23:46 +0000

What's the range of values for these? As Jason J suggested, the higher correlation for rebounding likely comes from the fact that it doesn't vary all that much. Also, I'd love to see stuff like the mean absolute error to get a sense of how much the error is on average when using last year's data to predict next year's data.

By: Jason J

Jason J — Tue, 29 Sep 2009 16:32:31 +0000

That jives with all the diminishing returns info that ABRmet produced regarding adding and subtracting great rebounders from teams. Basically rebounding doesn't vary THAT much regardless of personnel (though that's not to say that having a great rebounder doesn't promote winning by freeing up other players to run the break or get back on defense).

By: Charrua

Charrua — Tue, 29 Sep 2009 15:27:28 +0000

A factor here is the change in team rosters. We could interpret the results as suggesting that rebounding and turnovers are less susceptible to personnel changes and more a product of coaching strategy, for example.

By: Jason J

Jason J — Mon, 28 Sep 2009 19:53:58 +0000

Out of curiosity on how very bad free throw shooters who took a lot of FTAs effected overall league percentages for a season, I ran the numbers on Shaq’s effect in 2000 and Wilt’s effect in 1961. Dropping Shaq would have improved the league average from 75% to 75.3%. Dropping Wilt would have improved the league average from 73.3% to 75.1%.

Clearly the impact has to do with the size of the league. There were an additional 21 teams in 2000. Shaq took just 1.4% of the total league-wide free throws in 2000 (I was surprised too), while Wilt took 4.5% of the total league-wide free throws in 1962. Shaq shot 52.4% from the stripe, and Wilt shot 50.2%.

It’s worth noting though that the next season Wilt shot over 60% from the line and only had a 0.6% negative impact on league-wide FT% despite taking over 5% of the total FTAs.