Comparing the Streaks across time

Figures often beguile me, particularly when I have the arranging of them myself; in which case the remark attributed to Disraeli would often apply with justice and force: “There are three kinds of lies: lies, damned lies and statistics.”
Mark Twain’s Own Autobiography: The Chapters from the North American Review

That quote of course is a lie. The idea though is relevant to our upcoming discussion.

Unless, you’ve been living under a rock you know that a certain professional basketball team from the state of Florida (whose nickname rhymes with Beat) just had themselves the second longest win streak in NBA history and the longest since the NBA/ABA merger. This has of course sparked a debate about the significance and value of this achievement. Is it the greatest win streak ever? Does it pale in comparison versus the Lakers in 72 or even the Rockets in 2008?

33 Straight Wins for the 1972 Lakers. 27 Straight for the 2013 Miami Heat. 22 Straight for the 2008 Houston Rockets. At first glance, a comparison between these streaks seems fairly straightforward. Lakers then Heat then Rockets and make sure to drive home safely, right?

 

We will come back to this one of course :-)

We will come back to this one of course..

Wrong. There are many, many extenuating factors to consider. The rules of the game are different (hello three pointers!). The schedule of opponents and the schedule vary. The size and level of competition can be argued to not be the same given things like the NBA/ABA split. It’s enough to drive one to distraction.

Look a Kitty!

Look a Kitty!

Luckily, you have me and math to figure it out.

Time to do some digging and let’s start with the most obvious question: How did the NBA look in 1972?

The NBA expanded to 17 teams in the 1971 Season by adding the Portland Trail Blazers, the Buffalo Braves (nee Clippers), and the Cleveland Cavaliers begin play and divided into into Conferences (East and West), each with two divisions. This setup remained in place thru the 1974-75 season with the addition of the New Orleans Jazz. The pertinent fact for our discussion is the following equation:

Team point Margin per game = – 16.2 + 32.4* Win/Loss%

This gives the basic relationship for that version of the NBA between points and Winning. How does that compare to today’s NBA?

Team point Margin per game = – 15.5 + 31* Win/Loss%

Weirdly, even with the addition of the three point shot, a massive change in pace and style, and 40 years of distance that intrinsic point margin to win percentage relationship remains the same. In fact, if I look at game to game deviation between season team margin and actual game margin I get:

1971-72: 11.5 as your game to game point margin standard deviation

2007-08: 11.3 as your game to game point margin standard deviation

2012-13: 11.6 as your game to game point margin standard deviation

So margin of victory and amount wins can generally be treated as being relatively equal. 33 Wins in 1972 and 2013 are functionally the same.

Keeping that in mind, let’s take a look at each season in detail and set the stage. For this I broke out my full model and simulated out the 1972, 2008 and the current season accounting for opponents, schedule and altitude using all the tools I typically use for the power rankings .

1972 Power Rank

1972 was a season with some very interesting parallels to this year in that there were some very dominant teams at the top of the heap (the defending champion Bucks featuring Kareem,the eventual champion Lakers, the Rusell-less but rebuilding Celtics, the between championships Knicks, the Jerry Sloan-led Bulls pulling a reasonable Nuggets impersonation) . The Western conference was stacked and the Eastern conference sucked. Time is cyclical no?

Interestingly, Milwaukee ended the streak and surged past the Lakers for a while but eventually LA caught them and beat them in the Western conference finals on route to the championship. Make no mistake, the 1972 Lakers were a historically great team that had to go thru some heavyweights to get their streak and their rings.

2008 Power Rank table 2008 Power Rank

We’ve written plenty of Copy on 2008. The Celtics and Lakers after pulling off two massive trade heists for the dominant bigs of the time were the dominant teams. In fact, it really was all about the big men that year: KG going to Boston, Pau going to LA, Orlando putting a team of shooters around Dwight (might want to try that LA), Ben Wallace not being in Detroit and Houston losing Yao Ming.

Despite the adversity of losing their best player in Yao and playing in a historically stacked western conference, the Rockets still managed to pull 22 wins together. They’re the scrapper of this group.

As for the Heat this year?

Power Ranking As of 3/31/13

Power Ranking As of 3/31/13

Interestingly, the parallels to 1972 continue. A few dominant teams (the Heat and their finals rivals the Thunder, the deceptive Spurs).  A young scrappy team in Indiana to play the playoff victim, two aging question marks in Boston and New York. A murderous Western conference and a putrid Eastern Conference.

I would argue that the main difference is that the 2013 Heat streak is more about the Greatness of Lebron and taking his place in the basketball pantheon than a particularly great team. This is more 91 to 93 Bulls than 96 Bulls.

Now that the stage is set, let’s compare the streaks.

Comparison2

I tried to be as objective as possible and look at it from all the angles:

  • The Lakers win:
    • Length of Streak
    • Adjusted Point Margin for the season
    • Projected Win percentage versus average opponent at neutral site
    • Schedule strength (as measure by win percentage by average team versus same schedule
    • The likelyhood an average team could do the same. For the Lakers streak it’s .04 times in a billion attempts. They were also 15.3 points better than an average team during the streak.
  • The Rockets win:
    • The expected percentage of games they were supposed to win during the streak. The Rockets had the lowest average win probability for the games.
  • The Heat win:
    • The likelyhood of this team winning this many games in a row against that skid.

Let’s interpret shall we?  The Rockets had a tough road for them and the streak is impressive in context but it’s falls short of Heat streak and way short of the Lakers streak. The Heat did something historic and unlikely in that they played way beyond their observed level for a remarkably long amount of time. As I said, the earmarks of individual not team greatness.

The Lakers streak is unique, a different order of magnitude from the other two and most likely will never, ever, ever be matched unless some sort of weird player collusion happens.

Let’s not give Riley any more ideas.

-Arturo

 

 

 

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