Archive | January 2014

Using unpaired t tests of past regular season statistical rankings to predict nothing about the Super Bowl

I am especially excited about this year’s Super Bowl.

The season has been all about the Seahawks and Broncos and it’s nice to see players rewarded for regular season success.  But how do you even formulate an argument to pick the winner? Both teams finished the regular season with 13-3 records while performing similarly against playoff teams. Denver’s offense broke the single season record for points scored while Seattle’s defense is undeniably the best in the NFL.  Something has to give, right?

Here I’ve run some simple analyses on 7 regular season statistics that I hypothesize are best associated with team success to determine correlates of past success in the big game. I will use these data to predict the Super Bowl winner.

Methodology 

I went back and looked at the past 15 Super Bowls dating back to 1999.  This date was chosen as it was the year that the Minnesota Vikings broke the single season record for points scored, ushering in the era of some of the most prolific offenses in NFL history.  While Minnesota would lose in the NFC championship game that year, high-powered offenses including those of the St. Louis Rams, Indianapolis Colts, New England Patriots, New Orleans Saints, Green Bay Packers and this year’s Denver Broncos  would dominate the landscape of the league for the next 15 years.

For each participant in each Super Bowl between 1999 and 2013, I have assessed the team’s overall ranking in each of seven cherry-picked regular season statistical areas that I presumed had the best chance of correlating with Super Bowl success.  NFL rankings instead of raw numbers were used to normalize the data.  A parametric analysis was performed using an unpaired t-test to generate p-values for significance (p<0.05 is generally considered statistically significant).

GraphPad Prism software was utilized and did most of the work for me.  I am not a trained statistician by any stretch of the imagination, so if my inferences are stupid, kindly inform me where I went wrong. Here you can view each plot with it’s associated p-value.  Here is a sloppily produced PDF of the raw data that I used, obtained from NFL.com.

edit- I posted incorrect raw data of the composite rankings in the second PDF.  Here are the corrected values.

Elements assessed

1.  Quarterback rating

Justification:  The quarterback is the most important position in all of sports:  This is the only position player to touch the ball on every offensive play. The ability to make favorable decisions quickly can be the difference between a beastly and lousy offense.  Quarterback rating takes in multiple parameters including completion percentage, yards per attempt, touchdowns per attempt and interceptions per attempt, and uses them to gauge a quarterback’s success in all phases of his throwing game (running is not included).  While many people find the formula confusing – likely because they haven’t bothered to learn it – you will see that most established quarterbacks remain at the top of the list, year after year.

Results:  No statistical significance was found between the regular season passer ratings of Super Bowl winning quarterbacks and Super Bowl runners up (p=0.6205).  As a matter of fact, Super Bowl losing quarterbacks had a slightly higher mean passer rating compared with winners.

2.  Defensive yards allowed per game (YPG)

Justification:  If your opponent cannot move the ball, they are much less likely to score.

Results:  No statistical significance was found between regular season defensive YPG of SB winners and losers (p=0.8839).

3.  Defensive points allowed per game

Justification:  Teams can’t beat you if they can’t score.  This metric takes into consideration the “bend but not break” defense that may occasionally give up big plays but can shut offenses down in the red zone.

Results:  Again, no statistical significance was found (p=0.8373)

4.  Yards per carry

Justification:  Although the majority of a team’s yardage comes from passing the ball, the ability to run, especially with a lead, can be essential in securing a victory. A team’s yards per carry (YPC) best represents the success with which a team has running the ball.

Results:  Sadly, there is once again no statistical significance between winners and losers when it comes to regular season rushing efficiency (p=0.694).

5.  Turnover differential

Justification:  Teams that have a high proportion of takeaways to turnovers often win the field position battle and need to do less offensively to score.  Turnovers can derail even the most talented offenses.

Results:  No significance with a p-value of 0.6918.

6.  Sacks

Justification:  I once heard or read a statistic that teams only score on 7% of drives in which the quarterback has been sacked at least once.  If you pay attention, you will notice that sacks invoke huge momentum shifts and often drastically change field position.

Results:  A calculated p-value of 0.8618 indicates that a team’s regular season sack total has no correlation whatsoever with winning or losing in the Super Bowl.

7.  Field goal percentage

Justification:  In a league that strives for parity with a salary cap and revenue sharing, teams are so evenly matched that games frequently come down to the final play, which is often a field goal attempt.  Teams with successful kickers are more likely to win close games.

Results:  Despite falling short of the typically accepted cutoff for statistical significance of p<0.05, a calculated value of p=0.1384 for this parameter suggests that there is a much greater chance that regular season field goal percentage correlates with Super Bowl success compared with any of the other parameters tested.

Conclusion

Each Super Bowl is incredibly difficult to pick, although this one is especially challenging.  Vegas currently has Denver at -3, which is essentially an admission that it’s a toss.  Vegas always takes the better quarterback in these situations even if the data suggest that that may prove futile for the Super Bowl.

The Broncos and Seahawks were 1 and 2 respectively in the only category that came close to being statistically significant, field goal percentage.  Matt Prater and Steven Hauschka are both very good kickers.  Seattle’s composite score, obtained by averaging each of the 7 assessed statistics, was an impressive 4.6 while Denver was at 12.6, indicating Seattle’s advantage in overall team balance.  The comparison between composite scores of Super Bowl winners and losers yielded a p-value of p=0.5417.

Despite any real statistically significant findings, I will still offer a prediction.

Seattle (+3) swarms Peyton and his receivers on defense and takes this one, 24-21.

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I have a dream

I have a dream that one day my children will live in a nation where they are not judged by the automobile that they own, but by the content of their character.

Unless they buy a shit car.  Then I will disown their sorry asses.

I’ve been on the road a lot lately with the recent holidays and long weekends, and my journeys have inspired me to generate a compilation of the cars that will make me forever yearn for a red turtle shell.

The Ford Fiesta

This is not only one of the stupidest looking cars on the roads, but it also may take the award for most absurd model name.  Which demographic is the Fiesta supposed to be directed at?  This car does not invoke images of fun and happy Mexicans as its moniker may suggest.  Instead, it makes you sad and lonely because nobody loves or wants to be friends with somebody who drives one of these shitsicles.

The Chrysler PT Cruiser Fake Wood Panel Siding edition

I don’t think Walter Jr. understood how much worse it could have been…

As if Breaking Bad didn’t do enough PR damage to the PT Cruiser, Chrysler has these shart stains terrorizing the roadways.  I just don’t know why you want your car to look wooden.  Cars aren’t supposed to be made of wood.  My guess is that a wooden car would not be very practical.  Or safe.  Or aesthetically pleasing.  Believe it or not, I actually once encountered one of these in mustard yellow.  Let that sink in.

The former police car turned hooptie

In honor of MLK day, I will refrain from making any socioeconomically or racially disparaging comments about the people you typically see driving these things.  It’s like some people just can’t stay out of them.  Well there went that.

The pickup truck

I do understand the occasional necessity to haul shit around.  But I just don’t understand these shiny ass, brand new F350s I see roaming about suburbia.  If you need something to tote your, say fake wooden siding for your PT Cruiser, I’d suggest a beater.  The whole glamour/rugged pick-up truck juxtaposition just seems so…paradoxical.  But don’t tell that to everyone who bought a Yodge because of Ron Burgundy.

The Miata

My recent debacle in the snow with my Z was a harsh reminder of the practical sacrifices one must make to drive a sports car.  But for a 150 hp 1.8 L engine?  I think not.  Additionally, it is a little known fact that nobody has ever survived a crash in one of these shit-mobiles.

Anything that has a spoiler that shouldn’t have a spoiler

A sedan with a spoiler is like an old lady in a bikini.

It is said that spoilers on front wheel drive cars are useless because they are used to create down force on the drive tires.  I don’t know enough about physics nor care enough at the moment to accept or refute that.  One thing that I do know is that J-Roc and the Trailer Park Boys could probably build you a sweet wooden spoiler for that PT Cruiser of yours.

The flame motif

Speaking of the PT loser, it makes a return to the list, showing off this kick-ass flame job, which is not necessarily limited to the cruiser, but why not pile on as much as possible?  Like this car goes so fast that it catches on fire.  I mean, that is a good thing right?  What kind of person drives something like this?  Oh wait I remember.  An idiot.

The douchebag car

Can you envision it just from title?  The spoiler and tinted windows.  Low to the ground like a roomba.  Accelerates unnecessarily fast between stop lights in congested areas.  The douchewagon almost always comes equipped with a dude in a flat-brimmed hat with lots of tatoos.  Something about drifting? Yawn…

The bumper sticker car

You’re better off keeping your one sentence solutions to wealth inequality and third world famine to yourself.  When I’m sitting behind you in traffic, I already hate you by default for dicking around on your cell phone and braking too often.  The last thing I need is to be further outraged by your contradicting, bullshit opinions.

The horn blower

These cars must be defective or something.  Every so often, when a red light changes to green, some car in line will honk for like 5 seconds. I think it has something to do with electromagnetic fields from the traffic signal or something.  And then sometimes while I’m trying to sleep, I’ll hear one repeating incessantly in the parking lot just outside my window.  I often find myself worried that the car may be in trouble, but nobody seems to care much about it.  Eventually the battery just dies I suppose.

I have a dream that one day we can unite to rid the world of these inane automobiles.

I have a dream that red turtle shells exist.

M