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BBR Mailbag: The Most Offensively Balanced (and Imbalanced) NBA Finalists

Posted by Neil Paine on June 3, 2010

Today I have a mailbag question from our friend David Biderman at The Wall Street Journal:

Hey Neil,

I had an NBA playoffs question. I took a quick (really quick) glance at the Celtics, and the first thing that jumps out is how balanced their starting five was during the regular season. Is there any way to quantify how balanced a team is? If so, could we do this for NBA finals teams?

Absolutely; in fact, it's a concept I looked into a bit for these posts:

Spreading It Around
Championship Usage Patterns and “The Secret”
Championship Usage Patterns II
Championship Usage Patterns III: Regular-Season Teams Built For the Playoffs

However, I hadn't looked at NBA Finalists in particular yet, and I also would like to take this opportunity and try out a new metric to measure how balanced teams' starting lineups are.

The new metric (well, new to me at least) is called the Herfindahl-Hirschman Index (HHI), which measures how concentrated a market is among its firms. A monopolistic market will have a high HHI score, indicating that the majority of the market power rests with only a select few firms; conversely, a lower HHI score indicates a competitive market in which all firms have relatively equal shares. If you think of a basketball team as a market, you can apply this logic to a 5-man unit -- every player is working together to create points, but they're also "competing" against each other for touches and shots. A "monopolistic" lineup would be one where only one or two players take the majority of the possessions (think the 2000-02 Lakers with Shaq & Kobe), while a "competitive" lineup would be one where the offensive chances are distributed relatively evenly among the 5 players on the court.

So here's how I applied the HHI to Finals starting 5s... First, for every player in playoff history, I calculated Modified Shot Attempts (MSA):

MSA = 1.00 * (FG) * (1 - ((tmAST) / (tmFG)))+ 0.50 * (FG) * ((tmAST) / (tmFG))+ 1.00 * ((FGA) - (FG))+ 0.44 * (FTA)+ 0.50 * (AST)

This is essentially a measure of possessions used, except without turnovers because -- regrettably -- we don't have individual turnover stats for years before 1978. I then calculated the percentage of the team's MSA the player used when on the court (%MSA). For every Finals team ever, I isolated just their top 5 players in minutes -- not always necessarily their 5 starters, but usually the two groups are basically the same -- and scaled their %MSA to add up to 100% for that 5-man unit. I called the scaled %MSA term "share" -- as in market share, if the 5 man unit is a market and each player is a firm competing to use possessions. That way we can calculate the HHI, which is equal to the sum of the squared shares for a team. Here are the most imbalanced NBA Finals teams ever:

Year Team HHI Alpha Dog Share
1992 CHI 24.6% Michael Jordan 36.7%
1997 CHI 24.3% Michael Jordan 35.9%
1993 CHI 24.3% Michael Jordan 36.5%
1965 LAL 24.2% Jerry West 35.3%
2001 PHI 24.1% Allen Iverson 37.0%
1998 CHI 23.8% Michael Jordan 34.7%
1991 CHI 23.2% Michael Jordan 33.8%
2001 LAL 23.1% Kobe Bryant 30.0%
2002 LAL 23.0% Kobe Bryant 29.6%
1973 LAL 23.0% Jerry West 29.6%
1997 UTA 22.8% Karl Malone 32.2%
1962 LAL 22.7% Elgin Baylor 31.8%
2009 LAL 22.6% Kobe Bryant 34.3%
2005 SAS 22.6% Tim Duncan 28.3%
1977 PHI 22.5% Julius Erving 27.5%
1990 DET 22.5% Isiah Thomas 30.2%
1995 HOU 22.5% Hakeem Olajuwon 32.3%
1996 CHI 22.5% Michael Jordan 31.4%
1968 LAL 22.5% Elgin Baylor 28.4%
2007 SAS 22.2% Tony Parker 25.9%
1975 GSW 22.2% Rick Barry 29.4%
1972 LAL 22.1% Jerry West 29.9%
1989 DET 22.1% Isiah Thomas 29.0%
1988 DET 22.1% Isiah Thomas 30.3%
2008 LAL 22.1% Kobe Bryant 32.4%
1992 POR 22.0% Clyde Drexler 30.3%
1998 UTA 22.0% Karl Malone 31.0%
2010 LAL 21.9% Kobe Bryant 31.9%
1967 SFW 21.9% Rick Barry 31.6%
1969 LAL 21.9% Jerry West 30.1%

Wow, lots of MJ there. And at the other end of the spectrum, here are the most balanced Finalists ever:

Year Team HHI Alpha Dog Share
1973 NYK 20.0% Walt Frazier 20.8%
1982 LAL 20.2% Norm Nixon 22.7%
1972 NYK 20.2% Earl Monroe 22.6%
1958 BOS 20.2% Tom Heinsohn 22.7%
2009 ORL 20.2% Rafer Alston 22.4%
2006 DAL 20.3% Dirk Nowitzki 23.3%
1970 NYK 20.3% Willis Reed 24.1%
1961 STL 20.3% Bob Pettit 23.7%
1986 BOS 20.3% Larry Bird 24.0%
1977 POR 20.4% Lionel Hollins 24.2%
1996 SEA 20.4% Gary Payton 24.0%
1980 LAL 20.4% Kareem Abdul-Jabbar 25.1%
1984 LAL 20.4% Kareem Abdul-Jabbar 23.1%
1952 NYK 20.5% Max Zaslofsky 23.5%
1968 BOS 20.5% John Havlicek 23.5%
1961 BOS 20.5% Tom Heinsohn 24.6%
1987 LAL 20.5% Magic Johnson 25.2%
1976 PHO 20.5% Paul Westphal 23.8%
1981 BOS 20.5% Larry Bird 23.5%
1999 SAS 20.5% Tim Duncan 24.7%
1985 LAL 20.5% Magic Johnson 23.9%
1957 STL 20.6% Bob Pettit 26.1%
1983 LAL 20.6% Kareem Abdul-Jabbar 22.8%
1956 PHW 20.6% Paul Arizin 24.9%
1957 BOS 20.6% Tom Heinsohn 24.2%
1956 FTW 20.6% Larry Foust 24.6%
1953 NYK 20.6% Carl Braun 24.3%
1987 BOS 20.6% Larry Bird 25.6%
1955 SYR 20.6% Dolph Schayes 25.9%
1955 FTW 20.6% Larry Foust 24.7%

It's truly remarkable how balanced the 1973 Knicks were -- consider that a "perfect" HHI for a basketball team would be 20% (5*0.2^2), which was almost exactly the Knicks' score that year (technically it was 20.0328%, but that's close enough). Their top player by "share" was Walt Frazier with 20.8%; their starter with the lowest share was Bill Bradley with 18.7%. That's amazing, because it means on any given Knick possession, any of their starters were basically just as likely to put pressure on the defense. With easily the league's best estimated Offensive Rating in the playoffs (102.1, 3 pts/100 poss. better than the #2 Celtics), it's easy to see why those Knicks were a nightmare to defend that postseason.

But in total, how does team balance affect the outcome of a Finals series? Here is every Finals matchup since 1952, and how their HHI scores compared:

Year Winner Games HHI Loser Games HHI
1952 MNL 4 21.6% NYK 3 20.5%
1953 MNL 4 21.1% NYK 1 20.6%
1954 MNL 4 21.1% SYR 3 20.8%
1955 SYR 4 20.6% FTW 3 20.6%
1956 PHW 4 20.6% FTW 1 20.6%
1957 BOS 4 20.6% STL 3 20.6%
1958 STL 4 21.0% BOS 2 20.2%
1959 BOS 4 20.7% MNL 0 20.7%
1960 BOS 4 20.8% STL 3 21.6%
1961 BOS 4 20.5% STL 1 20.3%
1962 BOS 4 21.4% LAL 3 22.7%
1963 BOS 4 21.3% LAL 2 21.4%
1964 BOS 4 21.3% SFW 1 21.3%
1965 BOS 4 21.3% LAL 1 24.2%
1966 BOS 4 21.5% LAL 3 21.3%
1967 PHI 4 20.8% SFW 2 21.9%
1968 BOS 4 20.5% LAL 2 22.5%
1969 BOS 4 21.2% LAL 3 21.9%
1970 NYK 4 20.3% LAL 3 21.3%
1971 MIL 4 20.9% BAL 0 20.7%
1972 LAL 4 22.1% NYK 1 20.2%
1973 NYK 4 20.0% LAL 1 23.0%
1974 BOS 4 21.4% MIL 3 21.3%
1975 GSW 4 22.2% WSB 0 21.5%
1976 BOS 4 21.1% PHO 2 20.5%
1977 POR 4 20.4% PHI 2 22.5%
1978 WSB 4 21.0% SEA 3 21.6%
1979 SEA 4 21.4% WSB 1 21.0%
1980 LAL 4 20.4% PHI 2 21.5%
1981 BOS 4 20.5% HOU 2 21.1%
1982 LAL 4 20.2% PHI 2 21.5%
1983 PHI 4 21.0% LAL 0 20.6%
1984 BOS 4 20.8% LAL 3 20.4%
1985 LAL 4 20.5% BOS 2 20.7%
1986 BOS 4 20.3% HOU 2 20.7%
1987 LAL 4 20.5% BOS 2 20.6%
1988 LAL 4 20.9% DET 3 22.1%
1989 DET 4 22.1% LAL 0 21.1%
1990 DET 4 22.5% POR 1 20.7%
1991 CHI 4 23.2% LAL 1 21.4%
1992 CHI 4 24.6% POR 2 22.0%
1993 CHI 4 24.3% PHO 2 21.2%
1994 HOU 4 21.5% NYK 3 21.1%
1995 HOU 4 22.5% ORL 0 21.2%
1996 CHI 4 22.5% SEA 2 20.4%
1997 CHI 4 24.3% UTA 2 22.8%
1998 CHI 4 23.8% UTA 2 22.0%
1999 SAS 4 20.5% NYK 1 21.3%
2000 LAL 4 21.5% IND 2 21.0%
2001 LAL 4 23.1% PHI 1 24.1%
2002 LAL 4 23.0% NJN 0 20.7%
2003 SAS 4 21.3% NJN 2 21.4%
2004 DET 4 21.0% LAL 1 21.1%
2005 SAS 4 22.6% DET 3 20.9%
2006 MIA 4 21.6% DAL 2 20.3%
2007 SAS 4 22.2% CLE 0 21.3%
2008 BOS 4 21.5% LAL 2 22.1%
2009 LAL 4 22.6% ORL 1 20.2%

In the 58 NBA Finals from 1952-2009, the more balanced team won just 43.1% of the time -- and that's bad news for Boston, whose 21.2% HHI is lower than L.A.'s 21.9% mark. In general, this backs up what I found here, which was that teams with a more imbalanced attack, concentrating most of their possessions among only 2 players, were more successful that those who evenly spread their possessions among more of their starters. But before you write off the Celtics, remember that this group bucked that trend once before: in the 2008 Finals, L.A. was a team constructed much more like a typical NBA champ than Boston, but the Celtics prevailed anyway. Over the next few weeks, we'll find out if they can beat the odds again, or if the Lakers' traditional championship construction wins out this time around.

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7 Responses to “BBR Mailbag: The Most Offensively Balanced (and Imbalanced) NBA Finalists”

  1. Gerrit Says:

    Rafer Alston was the top usage man on last year's Orlando squad. Might be one of the reasons that they lost.

  2. Jason J Says:

    I think the key for that Knicks team was that everybody could really shoot, and nobody cared who got the ball. Pretty funny that the coach who won 10 titles with uber-usage kings Jordan and Kobe learned at the feet of Red Holzman who coached the champion with the most evenly distributed usage in league history.

  3. AYC Says:

    I'm surprised the 04 Pistons weren't one of the more balanced teams; I guess we can blame Ben Wallace...

    All this proves is that there's more than one way to skin a cat; dominant players win championships, but plenty of balanced teams have won it all too. I would compare the current Celts to the 82 Lakers; they have a balanced attack, but they are also a star-studded team of HOFers

  4. sidole Says:

    shoot,this was supposed to be a sweep.OK hope 4-1 Celts..

  5. Bob Says:

    It seems to me that there are a couple of interesting parts involved here. My theories are based on my current understanding of the salary cap (not sure about how that has worked historically)

    1) Every generation, there are anywhere from one to five truly dominant, high usage players, whose win total far surpass their peers. Lebron and Chris Paul (Durant this year as well) offer so many wins above replacement that they set they their teams far above the pack. These teams SHOULD naturally win more titles with their cap related competitive imbalance (caused by individual player max contracts).

    2) Relying on fewer players leads to greater team variance. Injuries and foul trouble (in the playoffs) are obvious issues here. But I would also ask if team construction as a whole leads to greater season long variability for many of the 2 superstar teams. I suggest that because, due to cap restrictions, these teams often have to depend on low usage, relatively cheap role players. They simply can't afford to spread the wealth as much due to their high investment in their star players. These role players can either be rookies or undervalued veterans, about whom there is less league wide information (especially given their future usage context). In any given year, these relative unknowns are probably more likely to under/over perform their projections.

    If their are four legitimate two superstar teams out their any given year and these teams are, on expectation, equal to their less variable egalitarian peers, it would makes sense that one of the high variance teams would hit it big on the variance express and win the finals. That probably depends on sample size (not a great stat guy) but I doubt 53 finals is enough to smooth it out.

    My guess is that some combination of theories 1 and 2 explain why 2 superstar teams tend to win more championships--at least in the current salary cap context.

  6. Ryan Says:

    I'm not sure if anybody has noticed the following.

    But for most Neil's position or player related lists lately, the weight of Michael Jordan is massive. He is misconstruing almost all lists. It's only fitting that the Alpha Dog takes his rightful throne in this category.

  7. Ryan. Says:

    Bob (and Neil alike), I suggest you watch this piece of commentary with Bill Walton:

    http://www.youtube.com/watch?v=RZ3GawN3SVU

    It's a great piece. He covers more ground on this subject, in laymen terms, than you would expect.