Monday, February 23, 2009

SAL and ALRL ratings after 2 races

SAL Driver
713 Matt Kenseth
165 Kyle Busch
150 Elliott Sadler
87 Jeff Gordon
83 Jimmie Johnson
80 Greg Biffle
36 Tony Stewart
23 David Stremme
10 John Andretti
7 Dale Earnhardt, Jr.
6 Mark Martin
5 Carl Edwards
4 Martin Truex, Jr.
4 Kurt Busch
3 Bobby Labonte
3 Juan Pablo Montoya

ALRL Driver
23% Matt Kenseth
19% Jeff Gordon
18% Jimmie Johnson
16% Kyle Busch
6% Elliott Sadler
4% Tony Stewart
4% Greg Biffle

Tuesday, February 17, 2009

2009 SAL and ALRL Rankings updated after Daytona

remember the SAL and ALRL rating descriptions from December. These data were very suggestive of potential championship performance throughout the year, so we will monitor these rankings during the season.

After Daytona, these are the current SAL and ALRL rankings are:

SAL Driver
474 Elliott Sadler
286 Kyle Busch
180 Matt Kenseth
49 Tony Stewart
28 Jeff Gordon
9 Dale Earnhardt, Jr.
8 Bobby Labonte
1 Mark Martin
1 Martin Truex, Jr.


52% Kyle Busch
16% Elliott Sadler
10% Tony Stewart
9% Jeff Gordon
5% Matt Kenseth
1% Dale Earnhardt, Jr.
1% Bobby Labonte
1% Mark Martin
1% Martin Truex, Jr.

Wednesday, February 4, 2009

Driver Skewness

Today's post is about skewness, an interesting property of distributions that you may remember learning about in your statistics courses.

Skewness measures how asymmetrical a distribution is. How can we apply this tool to enrich our understanding of driver performance? Intuitively, you would want a very positive skew, since that means most of your results are better (top 10s, top 5s, or even 1st place finishes). A negative skew would mean that you have most of your results on the far end of the spectrum (falling a lap or more down, DNFs, etc).

So if we measured some current and former drivers on the skewness of their career race results, what would we find? The full table appears below.

I think the results speak for themselves: skewness turns out to be a natural way to identify great drivers. As an example, it would be tough to argue that anyone else has outperformed Jimmie Johnson over the course of their career.

The table below also contains some surprises. For instance, it may be unexpected to see guys like Edwards and Hamlin this close to the top. Are they destined for great things ahead?

The simple statistic of "average finish" doesn't take into account the distribution of a driver's finishes. Skewness, however, takes that property into account, and thus might be the single best indicator of success in NASCAR.

Driver Skew
Jimmie Johnson 1.19
Dale Earnhardt, Sr. 1.16
Tony Stewart 1.10
Carl Edwards 1.02
Jeff Gordon 1.02
Denny Hamlin 1.00
Richard Petty 0.99
Mark Martin 0.95
Matt Kenseth 0.85
Clint Bowyer 0.76
Jeff Burton 0.72
Kevin Harvick 0.67
Dale Earnhardt, Jr. 0.66
Kyle Busch 0.59
Bill Elliott 0.57
Terry Labonte 0.56
Darrell Waltrip 0.55
Bobby Labonte 0.48
Greg Biffle 0.47
Sterling Marlin 0.36
David Ragan 0.32
Ken Schrader 0.25
Michael Waltrip 0.17
Kyle Petty 0.09
Ward Burton 0.08
Jeremy Mayfield 0.07
Joe Nemechek -0.15
Derrike Cope -0.25
Robby Gordon -0.28