Monday, February 27, 2012

College Basketball Team Rankings - February 27, 2012

My Old Kentucky Home 1
I've always liked Randy Newman's version
Google Visualization API Sample
Here are the College Basketball Team Rankings as of February 27, 2012.  These rankings use the Vegas point spreads to derive an implied team by team ranking.  My original post of the rankings has more detail on the methodology.


Kentucky is back on top again, with a half point lead over Ohio State.  Despite Ohio State's drop, the Big Ten overall gets a lot of respect in these rankings, with three of the top ten teams, and 9 of the top 64.  Also, the top 4 teams in Strength of Schedule (the SOS column) are all Big Ten teams.  It will be interesting to see if this holds come the NCAA tournament.  It's impossible to tell at this point as the Big Ten teams have not been playing inter-conference games (at least not ones with betting action).

Saturday, February 25, 2012

Visualizing the Knicks' Season

The Knicks have had their ups and downs this season, with Carmelo Anthony's various injury problems, Amare Stoudamire missing several games due to the death of his brother, and now the emergence of Jeremy Lin.


I thought it would be interesting to view those ups and downs through the Generic Points Favored (GPF) metric that I use for generating the weekly team rankings.  I'm also a big fan of Nathan Yau's work at Flowing Data (and his book), and this gave me a good opportunity to take a first stab at applying his principles to visualizing the metrics I provide on this site.


Click on the image below for a full screen version.  As you can see, the Knicks began the season with fairly high expectations from the betting market.  They hit their low point at around February 12, but have been on a steady climb since then.



NBA Team Rankings - February 25, 2012

New York Knickerbockers Baseball Club, circa 1847
The New York Knickerbockers Baseball Club
Here are the February 25, 2012 NBA Team Rankings.  These rankings use the Vegas point spreads from recent games to derive an implied measure of team strength (Generic Points Favored, or GPF).  By combining the point spread information with the betting over/unders, I can also decompose team strength into its offensive and defensive components (oGPF and dGPF).  For more detail, see the Methodology page.


The rankings were pretty stable this week, especially at the top, with no movement among the top 4.  The Heat have maintained their two point GPF cushion over the next best team, the Thunder.  This is consistent with the latest NBA Futures Odds, which has the Heat as the clear favorite at 6/5, and the next best team at 5/1 (the Bulls).

Monday, February 20, 2012

College Basketball Team Rankings - February 20, 2012

Here are the College Basketball Betting Market Team Rankings as of February 20, 2012.  These rankings use the Vegas point spreads to derive an implied team by team ranking.  My original post of the rankings has more detail on the methodology.


Despite losing on the road to Michigan on Saturday, Ohio State was able to reclaim its spot at the top of these rankings.  Most of the "subjective" rankings have Michigan State as the best team in the Big Ten at this point, and some even have the other Michigan ranked above them as well.

Saturday, February 18, 2012

NBA Team Rankings - February 18, 2012

Triple dead-heat
Triple Heat
Here are the NBA Team Rankings as of February 18, 2012.  These are a couple days late as I was busy with the day job.  In a nutshell, I am using the point spreads from recent games to derive an implied power ranking.  For more detail on the general methodology behind these rankings, refer to the Methodology page.

These rankings now incorporate the rest adjustments I described in this post.

The media hasn't been playing it up much, but the Knicks have experienced quite a turnaround recently, thanks to the strong play of an undrafted point guard (I think his name is Jeremy).  In a separate post, I'll take a brief look at how the betting market has reacted to this turnaround.

Thursday, February 16, 2012

NBA Home Court Advantage and Rest


UPDATE (4/7/2012): As mentioned in this post, there was an error in the original analysis.  After the correction, the back-to-back penalty changed from 0.75 points to 1.25 points.


The concept of rest, and its impact upon the game, seems to come up most often in the NBA, as compared to other sports.  In baseball, it's key when looking at pitchers, but doesn't seem to be a factor on a team level.  In the NFL, with teams getting one bye week per season, there is evidence that the extra week's rest gives a team a slight advantage coming off that bye week.  But this affects, at most, only 32 games of the 256 game regular season schedule.

The NBA, on the other hand, features matchups on a daily basis where one team has a rest advantage over the other.  If rest is defined as days since most recent game, half of the games played in the NBA from 2003-2010 were games in which one team had more rest than the other.  The purpose of this post is to determine to what extent rest asymmetries are factored into the betting lines of each NBA game.  I plan on using the results in future NBA team rankings.

Monday, February 13, 2012

College Basketball Team Rankings - February 13, 2012


Here are the College Basketball Betting Market Team Rankings as of February 13, 2012.  These rankings use the Vegas point spreads to derive an implied team by team ranking.  My original post of the rankings has more detail on the methodology.

Ohio State dropped out of the top spot to number two this week, with their Saturday loss against Michigan State being the key driver.  Kentucky now holds the number 1 spot with a slim half point lead.

Wichita State moved up three spots in the rankings to number 9 (identical to kenpom.com), and also managed to crack the Top 25 in the AP poll.

Thursday, February 9, 2012

NBA Team Rankings - February 9, 2012


Richard Moll mugs for the camera at the Governor's Ball held immediately after the 39th Annual Emmy Awards
Richard Moll ('Bull')
Here are the NBA Betting Market Power Rankings for February 9, 2012.  These rankings use point spreads and over/unders from the past three weeks to derive an implied estimate of team strength.  More at the Methodology page.


Summary


The top 3 reshuffled again, with the Bulls now on top with a Generic Points Favored of 7.0 points.  This is my fifth week of doing the rankings, and the top 3 each week has been the Bulls, Heat, and Thunder.


Dallas and Portland are interesting cases.  Dallas is ranked fourth, despite a 12th ranked Win/Loss record of 15-11.  It appears that the market expects the Mavericks to improve, now that Dirk Nowitski has returned from injury (despite the fact that they have gone 3-3 since he's been back).

Monday, February 6, 2012

College Basketball Team Rankings - February 6, 2012


Here are the College Basketball Betting Market Team Rankings as of February 6, 2012.  These rankings use the Vegas point spreads to derive an implied team by team ranking.  I view these as an additional benchmark one can use to evaluate team strength in the NCAA; something to compare against vote-based rankings like the AP and Coaches polls, and the fundamental stat-based rankings found at kenpom.com (and thanks to Ken for tweeting a link to this blog on Saturday - it doubled my cumulative page views in a matter of minutes).


The Rankings

Ohio State maintains its spot at the top, with a comfortable 2 point cushion over the next best team (which is significant, considering how bunched together the GPF's tend to be).

Friday, February 3, 2012

NFL Turnover Differential and the Point Spread


In the comments section of the Advanced NFL Stats post on the conference round post-season projections, an anonymous poster claimed the following:
For a very long period, winning NFL bettors made money simply by betting *against* the team with the better turnover difference. That's how drastically the public has overestimated the predictive value of turnovers. 
NFL turnovers are far more random than most people realize, and only correlate weakly with prior game performance.  Teams that have achieved strong season-to-date records by "winning the turnover battle" are more likely to regress to the mean.  Vice versa for teams with bad records due to poor turnover differentials.


I was curious to see if this market inefficiency actually existed and at what level.  A quick google search on the topic yielded conflicting results.  According to one site, teams with the unfavorable season-to-date turnover differential covered the spread more than 75%(!) of the time.  I would be skeptical of any statement of the form "When [simple rule], the spread is covered [x%] of the time", where [x] is anything north of 60%.  Especially if the rule can be applied to virtually every game.  A different site appears to claim just the opposite: you should try to pick teams that protect the ball well, since teams that win the turnover battle tend to cover the spread (then again, this site also claims to tell you how to pick NFL games "accuratley").

Thursday, February 2, 2012

NBA Team Rankings - February 2, 2012


Dwight howard 2009z
Here are the NBA Betting Market Power Rankings for February 2, 2012.  These rankings use point spreads and over/unders from the past three weeks to derive an implied estimate of team strength.  More at the Methodology page.


Summary


There was no movement among the top 4 this week, with the Thunder clinging to the top spot by a half point over the Heat.  


Orlando and (soon-to-be-traded?) Dwight Howard, on the other hand, are in free fall.  A week ago, the Magic were ranked 5th with a GPF (Generic Points Favored) of 4.5.  They have since dropped 10 spots to 15th and lost 3.5 points of GPF.  Using the GWP (Generic Win Probability) column, the Magic went from being a team expected to win 67% of its games, to a team expected to win only 54% of the time.