Matthew Yglesias has posted a comment on Competitive Balance in the NBA. His comment echoes one of the stories we tell in The Wages of Wins – specifically that the NBA suffers from a “Short Supply of Tall People.” In his comment, Yglesias links to The Wages of Wins Journal. Unfortunately, I do not think we have specifically gone over this particular story at our blog. I did post a comment on baseball that mentioned the story, but there is no post directly examining the competitive balance in the NBA.
Rather than write something, I thought I would just offer an excerpt from the book that details the evidence for our argument (for further evidence one is referred to our academic articles on this subject).
from pp. 61-62 of The Wages of Wins
At the other end of the extreme lies the NBA and the ABA. Each of these leagues is less competitive than any other league considered. At first this seems odd, since basketball is possibly the second most popular sport in the world. The problem with basketball, though, is not the population of people who are interested in playing. To play basketball you can’t just be interested. To play basketball at the highest level you generally have to be tall.
The average player in the NBA is 6’7”. The average American male stands about 5’10”. If we look at player rosters from ten consecutive NBA seasons beginning with the 1994–95 campaign, we find fewer than ten players logging significant playing time and standing 5’10” or smaller.34 At the other extreme we would note that only about 2% of adult males in America are taller than 6’3”, and a miniscule number are 6’10” or taller. Yet nearly 30% of the players employed by the NBA over the ten years we examined were at least 6’10”. So although basketball may be popular, to play at the NBA level you first must be tall. Unfortunately, as people in the NBA often note, “you can’t teach height.” As a result, the players the NBA requires are in short supply.
In the “Short Supply of Tall People” we compared competitive balance both before and after 1990. In the AL, NL, NFL, and NHL, competitive balance in the post-1990 era had improved. In the NBA, though, the 1990s was the least competitive decade in its history. Why? The NBA keeps adding teams but the short supply of tall people—yes, we love saying this—persists. There is only one Shaquille O’Neal. No matter what policies the NBA adopts, they cannot manufacture quality big men for every team. This rule doesn’t just apply to players like Shaq, but to smaller players like Michael Jordan. There is not an abundance of 6’6” people in the world either, and when you ask for a person of this height with Jordan’s skills, you are not going to unearth many candidates.
Given the supply of talent the NBA employs, there is very little the league can do to achieve the levels of competitive balance we see in soccer or American football. When your league depends upon a small population, the number of athletes close to the biomechanical limit will also be small. Consequently, games will often be between the good and the not so good.