Bobo strikes back (Tracking the Predictions week 1)

Posted on 11/02/2010 by

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Why should I refuse a good dinner simply because I don’t understand the digestive processes involved?-Oliver Heaviside (1850-1925), when criticized for his daring use of operators before they could be justified formally

Yesterday, I introduced one of my regular season weekly features, The NBA Now Rankings Week #1. Today we introduce another new feature: Bobo strikes back. This series will track offseason NBA predicions by WOW analysts and others across the web as the season goes along.

Before we get to that, for those who can’t get enough , the weekly podcast is up. Counseling is also available.

As you may or may not know the members of the WOW network (see sidebar) have engaged in a friendly contest (Wages of Wins Network 2011 NBA Super Stat Geek Smackdown). In it each of us who entered picked the win totals for every team as well as predicted postseason awards from the media and Wins Produced (let’s get this out of the way go here for  the Basics behind the math). In general, We did this by attempting to model the teams using Wins Produced to come up with a reasonable prediction for the season. At least some of us did 🙂

The reward?

We heard there might be an opening.

As part of the contest, we decided to track some well known models and personalities across the web who made offseason picks as well. We felt it was our duty to our audience and science to dispassionately analyze and report the numbers.

Potshots me? I'm just a cute kitten doing my part for science!

Before we get to it let’s provide some background.

The Contenders

Image courtesy of xkcd.com

From the WOW network of bloggers (go take a look):

  • My own models :
    • The Build (my effort to model every player and every team). There will be two versions of this one evaluated. One that accounts for strength of schedule and one that doesn’t.
    • Bobo the Monkey (my take at the dumbest possible model, this is just a team’s win total for last year)

If Bobo wins, we all lose.

From across the web:

Let’s look at the picks.

The Picks

Of note is that a few of the analyst (including a pro) did not bother to make sure the win totals added up properly. Shame on you 🙂

The Method for Evaluation

To evaluate how the predictions are doing, I take everyone’s raw wins predictions for each team and combine it with the equation for home team winning I came up with for a single game (see here for detail). To put it simply:

Probability of Home team winning a game = (Projected Wins Home Team-Projected Wins Road Team)/82 +.606

Then I worked it out for every game so far as follows:

  • If W% is greater than 60% call it a strong Win (W) for the home team
  • If W% is greater than 50% but less than 60% call it a weak Win (WW) for the home team
  • If W% is greater than 40% but less than 50% call it a weak Loss (WL) for the home team
  • If W% is less than 40% call it a strong Loss (L) for the home team
  • I then look at everyone’s hit rate for strong predictions and for all predictions.
  • I rank each model/analyst for both
  • I assign points based on ranking (double points for strong predictions since I value those more)

To me this is a fair test since the closer your predictions are to the actual shape of the NBA (in terms of how good team are) the better the win predictions will be

Let’s take a look at results thru 11/01/10
The Results so Far


Right now the WOW analysts are leading the pack. My two models are slugging it out with Evanz for the Lead. The bigger surprise for my models is at the bottom though were much like the Clippers making a run at the Wizards for the most lottery ball, our friends from ESPN are making a run at Bobo. I’d say more but I’d still  like to get linked by ESPN in the future. 


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