Here’s the poster for *He’s Just Not That Into You*. Notice anything interesting about the names?

All of those nine last names are in the first half of the alphabet. What are the odds?

Actually, nevermind, I’ll just tell you.

Last names actually aren’t evenly distributed throughout the alphabet. There are definitely more clustered towards the front half, but it’s tough to find hard numbers. A guy here claims that in the Cleveland phone book, 62.5% of the names are A-L. I’m not saying that Hollywood names follow the same pattern as Cleveland names, but it’ll have to do.

If the probability of one actor’s name being in the first half of the alphabet is 62.5%, the probability of nine actors’ names all being in the first half is .625^9. Which is .01455. So basically, the odds of this poster are 69 to 1. (Giggity giggity.)

A theory: maybe the casting director started at the top of his filing cabinet, and only got to L before all the parts were gone.

Rob#Rather than “odds” (or, in more precise statistical terms, “probability”), I think the more relevant statistical quantity is “expected value”.

By analogy: when I walk around my neighborhood, the odds that I run into a particular neighbor on one given day may be unfavorable; but, in the course of many trips around the neighborhood, I have more favorable odds of running into that neighbor at least once.

So, for the problem at hand: how many major movies come out in a given year? Let’s say there are 40. Now, for any given movie, let’s say there is a 1.455% chance that its 9 most prominent actors are all in the first half of the alphabet.

Therefore, you would expect (40*0.01455) = 0.582 movies in a given year to satisfy this condition – which works out to one movie about every couple of years.

In short, this phenomenon of alphabetical clustering may be improbable for a given movie, but it may not be so infrequent. A historical study of the alphabetical placement of each movie’s nine highest-billed actors might be the best way to answer your question.

(My father’s a statistician, and a very fine statistician is he;

All day he uses his slide rule to multiply by adding a log to another log, and when he comes home he multiplies by adding a log to me.)

fenzel#What were the odds that Ben Affleck was going to appear in a Sex and the City spinoff? How does the math for that work?

Dennis O'Brien#I think that whenever I see someone from Entourage in a movie (especially one I have no intention of liking), it helps to assume that Vincent Chase or Drama or whomever got a part in the movie and is playing the role.

For example: I like Poseidon’s Kevin Dillon scenes a lot better if I imagine that it’s a hammy performance by the faded TV star Johnny “Drama” Chase.