Posts on February 11, 2011

Scorecasting review
Mood: awake
Posted on 2011-02-11 02:02:00
Tags: reviews books
Words: 797

My latest Kindle read is Scorecasting: The Hidden Influences Behind How Sports Are Played and Games Are Won. It's a combination of Freakonomics (not that I've actually read it...) and Moneyball (but not just for baseball). I've read a few books like this but this was the most entertaining - the writing style is light and breezy but the analyses seem fairly well done. Some of my favorite chapters:

- Football teams should really really go for it more on fourth down than they do. One estimate showed that, in ~1000 fourth-down situations where they should have gone for it, they punted it away almost 90% of the time! The authors attribute this to loss aversion, specifically coaches that try strategies that are not "common sense" and fail are more likely to get fired, while if you do the "safe choice" even if it's less efficient, nobody holds it against you (i.e. "No one ever got fired for buying IBM"). (Incidentally, this is the second place I've read about stickK in the last month - it's a site where you set a goal for yourself and pledge to donate money to a cause you don't like if you fail. Something I'm considering for weight loss!) They also discuss similar seeming inefficiencies in basketball (pulling a star who's in foul trouble), baseball (always saving your closer for the ninth inning, even if there's a more important situation earlier in the game), and hockey (pulling the goalie when behind happens way too late). One prominent exception is Bill Belichick, who has such job security that he can do crazy things and people trust him.

- There are two fascinating chapters on the home field advantage. I will lay out the salient facts and present their conclusion:
* The home field advantage varies from sport to sport (from ~65% in soccer to ~54% in baseball) but doesn't vary much between different leagues of the same sport, and it's been remarkably consistent over time.
* It does not seem to exist for free throws in the NBA, or shootouts in hockey, or penalty kicks in soccer, or punts and field goals in football.
* Schedule padding in college football does account for about half of the home field advantage. In the NBA, teams get a more friendly schedule when they play at home (more days between games), which accounts for ~20% of the home field advantage.
* A lot of other things don't matter.
Their conclusion is (highlight to read) the biggest factor is "officials' bias" - not necessarily on purpose, but the home fans have a psychological effect on the officials, who call more fouls on the visiting team. In soccer, the length of injury time is affected. In baseball, balls and strikes are biased towards the home team, especially in high leverage situations. Notice that all of the situations where the home field advantage doesn't exist the officials have basically no impact on the outcome!

- There is a most excellent chapter on the "curse" of Chicago Cubs. First, the Cubs aren't really unlucky - they generally succeed in the playoffs as you would expect given their regular season record (i.e. not much). If you want an unlucky team, look no farther than the Houston Astros! (reached the NLCS 4 times, the NLDS 7 times, and no World Series wins) Interestingly, the St. Louis Cardinals have been surprisingly lucky. (all three teams play in the same division, sadly for this Astros fan)

So the question is why the Cubs don't put together a better team. Generally, there is a financial incentive for teams to do better: more fan attendance at games. The Cubs, however, have the least sensitive attendance with respect to their record - their attendance consistently hovers around 90%. This is very much not true for (say) the Chicago White Sox. And despite usually fielding a not-very-good team, the Cubs are the fifth most valuable franchise in baseball (thanks partially to WGN showing their games around the country).

So...what's up with the Cubs fans? Apparently they are loyal to a fault, and the atmosphere at Wrigley Field is more like a party than watching a baseball game. In perhaps my favorite statistic ever, attendance at Wrigley Field games is four times more sensitive to beer prices than to winning or losing! (and as such, beer is the third-cheapest at Wrigley out of all MLB ballparks) To quote the authors:

In other words, Cubs fans will tolerate bad baseball and high ticket prices but draw the line at bad baseball and expensive beer. That makes for a fun day at the ballpark but doesn't give the ownership much incentive to reverse the culture of losing.


Anyway, I enjoyed the book a lot and definitely learned a few things from it. Recommended if you like some combination of sports and statistics!


cleanin' out the old linkbox
Mood: tired
Posted on 2011-02-11 14:15:00
Tags: links
Words: 56

- A map of US states, labelled by which country their economy is the same size as. Texas is Russia!

- That Netflix graph of ISP download speeds I posted earlier - here's a cleaned up version that's much easier to read.

- A reminder: The IBM computer Watson plays on Jeopardy this coming Monday-Wednesday. Should be fun to watch!


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