Pre-season predictions: how have I done?

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Well, it's the first week of the new year, and I'm reading a book I received as a Christmas gift (thanks Mom and Dad) called Future Babble, which is written by Ottawa Citizen columnist Dan Gardner, who has also written the excellent Risk: The Science and Politics of Fear. The gist of Future Babble is that people suck at making predictions. For instance, in his latest article, Gardner says:

People want to hear predictions. And for the expert, there's no way he can lose. If the prediction hits, he can boast about it and reporters will cite it as proof of his wisdom. But if it misses, no one will ever hear about it again.

Heads, I win. Tails, you forget we had a bet.

Of course the rules of the game would be a little different if, at the end of the year, instead of asking for new predictions, we looked back at what was predicted to happen in the year ending. Think of it as holding people to account for the predictions they make.

While admittedly I don't consider myself an "expert" and I've previously noted the difficulty of predicting the outcome of the NBA season before the season starts, I did make some predictions that we could examine. I'd  like to be accountable and trustworthy, and I'd like to learn from my mistakes, so let's start out with my predicted NBA standings - how have I done so far (full spreadsheet here)? All win totals are accurate as of January 5, 2011.



Included in the table are several columns - predicted wins (what I predicted before the start of the season), current record, a simple win projection (which multiplies current winning percentage across 82 games), a point differential win projection (which uses Arturo's formula to determine wins via point differential), and the average difference between my pre-season predictions and the two projection methods.

What does the table show? Generally, I was either really close or way off - not much in between. Thirteen of my predictions came within 5 wins of the current projections, 12 predictions were off by ten or more wins, and only five predictions were off in the 5-10 win range. The teams I overrated the most: Sacramento (a whopping 22.4 wins off target), Cleveland (21.3 wins off), Portland (18.3 wins off), Golden State and Philadelphia (each 17.1 wins off), and New Jersey (16.3 wins off). The teams I nailed: Orlando (0.4 wins off), Chicago (0.6 wins off), the Lakers (1.0 wins off), and (of course) Toronto (1.1 wins off). Where did I go wrong with those six teams?

Sacramento



Carl Landry has fallen into the toilet and can't get out, Dalembert isn't playing up to his usual standards, and I was burned by one rookie (Cousins) and one second-year player (Evans). As we saw with Kevin Durant, sometimes the rookies that we think are going to be good NBA players start out slowly, so either of these two players could turn it around in the future. Of course, some players never get it - we've been saying the same thing about Michael Beasley, who is still not playing well during his third season.

A few players - led by Udrih, Casspi, Garcia, and Head - have out-performed my expectations, but if you combine the bonus wins provided by every player in the green (6.6 wins) it is barely enough to make up for Evans or Landry by themselves.

Cleveland



J.J. Hickson has, to paraphrase Jason Kidd, performed a complete 360 this season. Last year Hickson was just a shade below an average player, and this year he is giving the lovable Andrea Bargnani a run for his money in the competition to win the Darius Songaila award. Hickson is only 22 years old, so his volatility is somewhat understandable...but you can't blame me for not forseeing such a huge change. Antawn Jamison is finally starting to show his age - you could argue I should have seen a decline coming there. Mo Williams is also down this year - his shooting efficiency (which is supposed to be his strong point) is way down and his turnovers are up, but thankfully he's been able to up his assists. Other than that, the other players who haven't met my expectations have only been slightly below what I had penciled them in for; however, all those small changes add up quickly.

Andersen Varejao is really the only player on the team who has stepped up his play this season. It seems that the turmoil associated with LeBron's departure has really messed with the players who stuck around - probably one part new roles and one part psychological.

Portland



The big letdown here is Brandon Roy - I expected him to account for 10.8 wins on the season, and right now he is not even on pace to win a single game. And even though I only allocated 800 minutes to Oden, his rate of production is so good that I expected him to account for 4.7 wins. Well, there's about 16 wins out the window. Joel Przybilla is also on pace to be down about 5 wins, but, as he returns from injury, his minutes will go up and so will his projected wins. The rest of the players who have let me down have combined to produce 10.4 wins fewer than I expected.

On the plus side, the two old guys (Miller and Camby) have upped their games, as has Batum and Mathews. These four players have combined to exceeded my expectations by 10.7 wins. It's a testament to the Blazers that they've been able to stick around 0.500 with injuries to some of their top players.

Golden State



The big problem with my Warriors prediction has been the play of David Lee. After receiving an early Christmas present from Wilson Chandler, Lee had a serious infection in his shooting arm and hasn't played well since. The other players that are hurting my prediction are Stephen Curry, Reggie Williams, and Louis Amundson - all players with limited playing histories.

On the plus side, human sine wave Monta Ellis is playing better than I expected...for now.

Philadelphia



The Sixers are the only one of these teams to be off in a positive direction - I predicted they would win around 19 games, but right now they're on pace for 39 wins. The big differences are due to the return of Elton Brand (finally) and Andres Nocioni, the emergence of two young players (Jrue Holiday and Thaddeus Young) as average to above-average players, and a lower than expected amount of minutes being allocated to unproductive players (perhaps coach Doug Collins is actually helping the team in this case?).

While he has been slightly better than I expected, Iguodala's minutes have been low due to injuries. Rookie Evan Turner hasn't lived up to expectations so far, and Louis Williams has offered less than he has in the past. Still, things are much rosier in Philadelphia than I thought they would be.

New Jersey



Brook Lopez is another young player who seems to have taken a huge step backwards, as has old WP favourite Troy Murphy.  Additionally, Outlaw and Terence Williams aren't playing the way I thought they would.

On the bright side, ex-Raptor Kris Humphries has improved drastically, nearly making up for Murphy's poor performance on his own (he's also the star of my Wins Score Association fantasy team). New Jersey should also get a little better as Vujacic gets a larger percentage of the team's playing time.

Once the season finishes, I'll take another look back and see if anything's change significantly. Hopefully things regress back to my expectations!

 - Devin