The large supply of tall people
In this New York Times article from three weeks ago, Dave Berri, co-author of "The Wages of Wins," once again argues that the relatively low level of competitive balance in the NBA is due to the "short supply of tall people":
"The population of [necessarily tall] athletes the N.B.A. draws upon is quite small. … As the evolutionary biologist Stephen Jay Gould observed, when a population is relatively small, the difference between the very best and the average athlete will be quite large. In other words, when your population of athletes is small, your league will have less competitive balance."
I have previously made two points in response to this argument. First, there are other, stronger reasons that the level of competitive balance in the NBA is low. And, second, every sport has specialized requirements for its athletes -- why should height be any different?
It's the second point I want to address in more detail here.
Berri asserts that basketball players need to be tall. Which is true. But, obviously, height isn't enough. They also need to be able to shoot straight. They need to be able to anticipate plays. They need to be able to read a defense. And so on.
Why, then, should height be special? Isn't there equally a "short supply of people who can feed a teammate with a blind pass?" Isn't there a "short supply of people who can make a difficult fadeaway jumper?"
And, as I wrote previously, Wayne Gretzky saw plays unfold in slow motion, which gave him extra time to react. This made him perhaps the greatest playmaker in hockey history. You've got to think that even among all the hockey players in the world, there's a very short supply of people who can read plays anywhere close to the NHL level.
Why makes height different from shooting, or playmaking? For almost any skill (or "characteristic," if you don't consider height a skill), the population will possess it in a normal distribution. Professional athletes are drawn from those winding up in the far right tail of that distribution -- the best of the best (or tallest of the tallest). Of course, any sport requires not just one skill, but many. So an NBA player could probably be only "above average" in some areas, so long as he's *way* above average in enough other areas.
But there's a short supply of humans who are in the right tail of any and every normal distribution. Again, why should height be different? I see three ways height is different, and both of them work *against* Berri's argument.
First: not all basketball players are tall. A quick check of the Detroit Pistons roster shows that four of their players are 6'3" or shorter. It's not really rare to be that tall. I know several people who are around 6-3.
But how many people do I know who can beat out even one Detroit Piston in any basketball-related skill? Probably none. In passing, shooting, or dribbling, any NBA player could beat any of my friends with no effort at all.
What does this mean? That while height is important for a basketball player, it appears to be almost the *least* important of all the skills! If you count all the men in North America who are at least as tall as the fourth-shortest player on an NBA team (6-3), you'll get a pretty high number. If you count all the men in North America who can block shots at least as well as the -fourth-worst player on an NBA team, you'll get a pretty low number.
When you look at it this way, there's comparatively a pretty *large* supply of tall people.
Second: tall men -- really tall men, say 6-7 or such -- may be fairly rare in the general population, but they are easily noticed. So while there might be a short supply of tall people, probably all of them have tried to play basketball! That is, suppose that in the general US population, men who are 6-7 are exactly as rare as men who can hit a fadeaway jumper under pressure with two seconds left on the shot clock. You'd find more of the former in the NBA than the latter. Why? Because almost all tall teenagers attract attention as basketball players, and they all will have had tryouts. Meanwhile, not-so-tall teenagers who might have had basketball skills could wind up not playing at all (especially if they are younger than their peers, and so temporarily smaller), or concentrating on other sports.
Relative to other skills, and considering only the population who considers playing baskeball, height is again in larger supply, not shorter.
Third: tallness is evident early, but basketball skill may develop later. According to Wikipedia, even Michael Jordan "was not initially a standout player for the North Carolina Tar Heels." In any sport, history is full of players drafted in the very late rounds who turn out to be superstars, and there are lots of players who unexpectedly develop into elite players even after making the big leagues.
"Tall" is obviously easier to scout for than other skills. How many teenagers would have pursued an NBA career, but didn't know they would eventually be able to pass and shoot and read a defense extremely well? Probably lots. How many teenagers would have pursued an NBA career, but didn't know they would eventually be extremely tall? Probably very few.
Again, the height requirement means that more of the best players in the world will make the NBA -- not fewer.
1. Height is not as rare in the general population as other basketball attributes, which suggests that it's less important.
2. People with height are almost 100% likely to consider and pursue basketball, unlike people with other basketball skills.
3. Height is evident early in a player's life, unlike other basketball skills.
The fact that height is more important in the NBA than in other sports results in an increase in the basketball-suited population that actually pursues the sport. The market for professional basketball players is much more efficient at recognizing productivity when it appears in the guise of height than when it appears in other ways.
And so I don't think it's correct that NBA play quality -- and therefore competitive balance -- is reduced by a shortage of tall players. If anything, height is *more* abundant than other skills.
The argument should go exactly the other way. The fact that height is important in the NBA results in *more* competitive balance compared to other sports, not less.