The (Usual) Folly of Probability Matching

Generally speaking, people are fairly decent at learning how often things happen.  For example, if you asked someone to predict a bunch of coin flips, they would come out pretty close to 50%.  They aren’t especially good at doing other, closely related things, like shifting quickly if those odds changed or making the sequence of predictions properly random, but at least they do a good job of probability matching – that is, they will respond in proportions equal to the actual outcome probabilities.  Why in the world would you care about that?  Because it’s usually actually a bad idea – unless you’re filling out your bracket.

Statistics Can Lie… Sometimes

Just wanted to pass along this post, which I think does a neat job of describing why some scientific studies seem to disagree from week to week (have some wine! no, don’t have wine! coffee is good for you!  caffeine is bad!).  And a quick thought on how it applies to sports below the jump.

A Quick Thought on Plus/Minus

The Wages of Wins guys have a post on plus/minus over at their blog, and Tango has something of a reply post over at his blog.  I thought I would throw in my two cents.

The Better Team Doesn’t Always Win

There’s an interesting post over at the Harvard Sports Analysis Collective on the accuracy of the power rankings for ESPN versus Football Outsider’s.  I mostly just wanted to point to it, but I have a couple thoughts below.

Randy Moss is Pretty Good

Before the Super Bowl Randy Moss got some headlines for saying that he’s the greatest receiver ever to play the game.  Not surprisingly he caught some flack for that, probably because he forgot that his current team used to have a guy named Jerry Rice play the position pretty well.  Some people also have personal reasons for bumping Moss down; they feel that he didn’t always play his hardest or that his personality wasn’t so hot.  In his last article for the season, TMQ went so far as to say that Moss doesn’t even break his top 10.  That seems a little harsh to me.  So how good has Randy Moss been?

Super Bowl Recap

I watched the Super Bowl last night with a few friends and when the game was over, they were all either disappointed or unimpressed with the game.  I think it’s because no one had a vested interest and so they just wanted something underdog-y to happen; when the 49ers went down early and didn’t complete the comeback, I think that was the disappointing part for them.  As for me, I thought it was a really entertaining game: it had good play, a big comeback, big plays, big hits, and some interesting decisions.  The underdog won and the game hit the over.  If that isn’t exciting, what is?  Some thoughts on the game after the jump.

Accuracy and Precision

As I’ve been thinking about my football models and their less-than-stellar season of predictions, I was reminded about the distinction between accuracy and precision.  Depending on the circumstances, those two words can mean a lot of different things.  If you’re watching a football game and the announcer says the QB has an accurate arm, and then two quarters later says the guy is very precise with his throws, he probably meant the same thing each time and happened to pick different words.  But in at least some science/math circles, accuracy and precision mean different things.  In the interests of stats literacy, I’ll talk a bit about what they mean and how it applies to sports.  Head’s up: this is a long one, so grab a snack or something.