Checking 2013-14 NBA Win Predictions & Projections

With 2013-14 NBA regular season in the books it’s time for some fresh projections about the NBA playoffs!
But wait a second, aren’t we forgetting about similar predictions for the regular season? As usual I’d like to expand the effort of APBR community in an attempt to measure how successfully basketball writers, bloggers and authors predicted what will happen during the regular season regarding teams’ wins.
So which writer, blogger or author had the most accurate projections before the 2013-14 NBA season?

To answer this question I saved on my hard drive predictions in early November [it’s a reason why not all of the links below work, they’ve changed since then] from most popular sites and some googled sources [but it’s not a closed list so if you want to add your’s predictions let me know in the comments] and compared them to actual wins for each team by Root Mean Square Deviation which is essentially average difference between each prediction and final total wins in terms of absolute value. Results of this exercise are in the table below…

But please keep in mind two important notes:
1) don’t think or assume it’s all about the skills of people involved because randomness plays a huge part here… injuries and trades in most cases simply couldn’t have been predicted before the season but they affected some of the results in a big way [for example, Gay trade anyone? Or Horford’s shoulder…].
Personally I treat it as fantasy basketball on a team level and I’m more interested in the year-to-year patterns than in actual results for one particular season because it’s basically a sample of one.

2) in most cases entries next to each other are interchangeable in terms of accuracy because difference between them can be translated into “2-3 more/less wins in the right direction would flip them”.

Onto the table…

 

Checking 2012-13 NBA Win Predictions & Projections

Just before every NBA season most basketball writers, bloggers and authors try to predict what will happen in the next year which is usually fun stuff to read and discuss. But I’ve always felt there’s a half of the picture missing – accountability for those predictions.
Recently pundittracker.com started to track single-winner picks which is great but I’d like to continue this blog’s “tradition” with comparing wins projected before the season to the actual ones after the season.
So which writer, blogger or author had the most accurate projections before the 2012-13 NBA season?

To answer this question I gathered predictions in early November from most popular sites and other googled sources [btw, it’s not a closed list so if you want to add your’s predictions let me know in the comments] and compared them to actual results by Root Mean Square Deviation which is essentially average difference between each prediction and result in terms of absolute value.
If you want to play with numbers or check any single entry just download NBA Predictions Accuracy 2012-13.pdf but if you are interested only in the results they are in the table below…

But please keep in mind two important notes:
1) don’t think or assume it’s all about the skills of people involved because randomness plays a part here… and it’s hard for the better example than Minnesota Timberwolves in 2012-13. Literally everybody thought they would be better this season but they were crushed by injuries and in the end the best prediction for this team turned out to be from… last years’ adjusted wins! So if someone predicted 45 wins for them his result was punished by bad luck more than someone who predicted 35 wins for them.
Well, unless someone can predict injuries…

2) in most cases entries next to each other are basically interchangeable in terms of accuracy because difference between them can be translated into “2-3 more/less wins in the right direction would flip them”.

Onto the table…

 

NBA 2011-12, Revisiting Predictions for Wins

After checking accuracy of predictions for wins in the NBA in 2010/11 and two earlier seasons I’m hungry for more and thanks to passing time I can add most recent data! Farewell 2011/12! So which writer, blogger or author had the most accurate wins predictions for that lockout-shortened season?

To answer this question I gathered last season’s predictions from most popular sites and other googled sources [btw, it’s not a closed list so if you want to add your’s predictions let me know in the comments] and compared them to actual results by Root Mean Square Deviation which is essentially average difference between each prediction and result in terms of absolute value. If you want to play with numbers or check any single entry just download NBA Predictions Accuracy 2011-12.pdf but if you are interested only in the results here they are…

 

More years of data for Accuracy of Win Predictions

My first reaction after I’ve finished post about Accuracy of Predictions for Wins in 2010/11 was this: “that’s nice but what about consistency of authors?”. Are writers and bloggers consistent over time or is it basically a semi-random outcome every year? Is it an educated guess or just a guess by educated people?

To answer this question I simply needed more data and because I didn’t want to wait a couple more years I went the other way – into the past. I collected some predictions for NBA standings before 2009-10 season and before 2008-09 season [btw, it’s not a closed list so if you want to add any predictions let me know in the comments]. Then I again compared them to actual results by Root Mean Square Deviation [read post about 2010/11 for explanation]. If you want to play with numbers or check any single entry just download NBA Predictions Accuracy 2008-2009-2010.pdf but if you are interested only in the results here they are…

 

Accuracy of Predictions for Wins in NBA in 2010/11

Just before every NBA season most basketball writers, bloggers and authors try to predict what will happen in the next year which is usually fun stuff to read and discuss. But as with mock drafts I’ve always felt there’s a half of the picture missing – accuracy of those predictions.

I’m sure there were many efforts like on APBR forum which dealt with this issue locally but as usual I’m curious about the big picture which in this case means… whole basketball-oriented part of the internet.
I have many questions related to this topic but let’s start with a simple one:
which writer, blogger or author had the most accurate wins predictions last year?

To answer this question I gathered last season’s predictions from most popular sites and other googled sources [btw, it’s not a closed list so if you want to add your’s predictions let me know in the comments] and compared them to actual results by Root Mean Square Deviation which is essentially average difference between each prediction and result in terms of absolute value. If you want to play with numbers or check any single entry just download NBA Predictions Accuracy 2010-11.pdf but if you are interested only in the results here they are…