Monday, November 20, 2006

Increasing NBA competitive balance

Today, on the "Wages of Wins" blog, David Berri reprises an argument from the book, that NBA competitive balance is low because of "the short supply of tall people." He writes,

"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."

I disagree. There are many ways the NBA could substantially increase competitive balance. Here are a few. Some are more realistic than others, of course:

-- add a 4-point, 5-point, and 6-point line behind the 3-point line.

-- make the 3-point shot worth 5 points.

-- make a "nothing but net" shot worth an extra point.

-- make the hoop a few inches smaller.

-- make the shot clock 12 seconds instead of 24.

-- overinflate the ball, like they do in carnival games.

-- make games 20 minutes in length instead of 48.

-- adjust the draft rules so that the worst teams get even more draft choices and the best teams get even fewer, thus more quickly evening out team talent over time.

-- institute a "talent cap" instead of a salary cap, so that teams with too many good players have to get rid of some.

-- count young players at estimated free agent value towards the salary cap, so that teams can't dominate just because of drafting ability.

-- divide the game into seven "quarters" instead of four. Whoever wins 4 out of 7 quarters is declared the winner of the game.

-- like in baseball, allow each player to take only about 1/9 of his team's offensive opportunities.

-- like in soccer and hockey, allow goaltending.

-- like in football, give teams points only when they complete a long sequence of successful plays – for instance, give them a seven-point "touchdown" when they score on six consecutive posessions, or a three-point "field goal" when they hit two three-pointers in a row.

(Just for one example, making the hoop smaller would help substantially. I simulated a simplified 100-possession game between a team that shoots field goals at 50% vs. a team that scores at 48%. The first team's record was .620. Then, I changed the probabilities from 50%/48% to 40%/38.4%. The first team's record dropped to .590.)

The point, of course, is that the rules of the game are at least as important as the supply of talent. For a full exposition of this argument, see Roland Beech's review
here. TWOW's recent rebuttal to Beech is here. (My own argument is on page 3 here.)

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At Tuesday, November 28, 2006 3:05:00 PM, Anonymous Anonymous said...

If I understand Berri's argument, it goes like this:
1) the competitive balance in basketball (as measured by SD in win%), unlike other sports, has not increased in recent decades;
2) this means that the variance in player abilities hasn't decreased, and
3) the best explanation for this is the 'short supply of tall people.'

Once again, this is a very odd line of reasoning. First, variance in team performance may not track variance in player performance. Many intervening factors can change the distribution of talent w/in leagues (draft rules, revenues, salary caps, etc. etc.). Plus, because the structure of the game results in very high W% for the best teams, it would probably take a huge change in talent variance to make the game more 'competitive' at the team level. So the logical thing to look at is the actual distribution of individual player talent over time. But as best I can tell, Berri doesn't do this (just as he never looked at correlation of player talent and salary, while concluding the link is weak).

* * *

And in at least one important respect, we know there has been a decrease in talent variance. In the 1950s and early 60s, a few big men (Chamberlin, Russell) could totally dominate the game. They set records that still haven't been broken, and probably never will be. Now, every team has big men and it's much harder to gain an edge strictly through height.

Ironically, the dominance of Chamberlin and Russell is very much like the .400 hitter that S.J. Gould was writing about, and whose theory Berri is applying here. His mistake is treating height as some kind of arbitrary job qualification that shrinks the talent pool, rather than as itself being a crucial skill for basketball players.

If we had a time machine and could bring back a 1955 team and have it play a few games against any current NBA team, we would see what competitive imbalance really looks like.

At Tuesday, March 08, 2016 4:28:00 PM, Anonymous Daniel B said...

Height probably has something to do with it, but mostly it's that in basketball one guy makes a much bigger difference than in most other sports.

One dominant football player on an offense or defense with 10 average teammates has much less effect to boost his team than does one dominant basketball player on the floor with 4 average guys. And not just b/c he's 20% instead of 9% of the team, there are many other factors that let one guy be dominant. For example, passing rules: if an RB in football carries the ball, all 11 defenders can run at him if not blocked properly and he generally has to keep the ball and try to beat them all himself. If a basketball player has all 5 defenders converge on him, he has 4 choices of teammates to pass to - so a dominant basketballer is harder for the D to stop than dominant footballer is.

Also, some sports just have more luck than others. Baseball has a lot. It is much harder to precisely control a ball that you hit with a stick and the opponent throws at you, then it to control one you guide with your own hands. A basketball shooter has more control over if his shot connects or not than a batter does over whether his hit is caught on the fly or not. Also, the consequences are more drastic - if he fails to avoid a fielder, it's an auto out. If a shooter misses, his team can still rebound and suffer very little (unless time is a factor).

American football and soccer have less luck than baseball, but still more than basketball, because they are more "all or nothing". In a game where the final ends up around 100, missing out on an individual chance for 2 or 3 isn't a huge deal. In a game to around 30, missing out on a chance for 7 or even 3 can be huge. In a game to around 2, missing out on a chance for 1 is killer. One (un)lucky bounce in football can swing 2 touchdowns, which could be a very large portion of the entire game's scoring. To really simplify it, let's say each soccer team in a game gets 20 looks which each have a 5% chance of a goal. Each side's average is 1 goal, but quite likely you win if you get the 1 and lose if you don't. A lot left to the micro-variables with very little chance to atone for a difference of even 1.

Please note I'm not saying anything bad about baseball, football, or soccer. Just analyzing the difference as to how likely the "better" team is to win, and why. Didn't include hockey as I know essentially 0 about it.


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