The 2015 NBA Playoff Preview

“Come, Watson, come!” he cried. The game is afoot.”
― Arthur Conan Doyle, The Adventures of Sherlock Holmes

Let’s set the mood first.

 

I’m 25% more pumped each time I watch that.

I’m late with the article this year but I got all the numbers up before the bell. Here’s the proof.

Let’s blow that up for reference.

Round 1 Picks

My mission to give you predictions and opinions that are grounded in proper science continues. That is the full slate of probability for every first round series of the 2015 NBA playoffs.

Now, let’s talk about the background like every proper scientist should.

The Method

The method really has three parts:

  • Setting the player Value
  • Projecting Minute Allocation
  • Running the Playoff Model

One important note is that playoff experience matters. I have been pointing this out for a while. Basically, playoff vets get favorable calls. To account for that bias, I’ve given those teams that feature experienced playoff performers a 4% boost (or about half of the basic homecourt). This is forever to be known as the Sacramento Discrepancy (for this particular first round you could call it the Northern Gap).

Additionally, a similar effect is seen for an outsized coaching advantage. This one is known as the George Karl Effect (as in “Oh my God, is that Randy Wittman’s music?!”).

For setting the player value, I ended up using the readily available post All Star Break numbers (from this site) for every player. The next bit is the tricky part. You have to guess at what the playoff minute allocation will be for each team. The key idea here is the half baked notion.The half baked notion is this: what wins in the regular season is not necessarily what gets you the trophy. What’s the difference? Minute allocation and how wins are affected by that allocation. We continuously hear terms like playoff rotation and playoff minutes thrown around near playoff time. When we take a look at the data, we’ll see that the pundits may just be right (hell has officially frozen over). The half baked notion tells us that a good deep team filled with average and above average players will get you in the playoffs, but to get far in the playoffs you need your wins to be concentrated in your Top 6. To illustrate, let’s look at the regular season data. I’m using all the data from every season since the merger. I will be ranking the players on each roster by minutes played and then allocation wins accordingly. The data looks like this: A few interesting points from this table:

  • Your starting five account for 82% of your wins in the regular season.
  • Your second unit is important over the course of an 82 game regular season, accounting for 18% of your wins
  • After that, everybody else is statistically meaningless.

Now let’s look at the playoff data. Again, I’m using all the data from every season since the merger. I will be ranking the players on each roster by minutes played and then allocation wins accordingly. The data looks like this:

You can clearly see the obvious differences:
  • Your starting five account for 94% of your wins in the playoffs.
  • Only the first guy of your bench matters accounting for 5% of your wins
  • After that, everybody else is statistically meaningless.

 Does the pattern hold if I sample more recent playoff data?

Yes it does. Using that knowledge and some handy, dandy minute projection tools I had on my computer for some strange reason I came up with this: Rosters 

You’ll note that this year I focused on post trade deadline numbers.  Given the craziness that went on, I thought it was the right call. Also keep in mind that this is my best guess. At this point we’re trying to read the minds of some real luminaries, and if I were that good at it, I wouldn’t be working for a living. It will get easier in Round 2 of course. The compiled result looks like so:

Playoff Power rank

The margin between the Spurs and the Warriors is razor thin. The Clippers also got a bum deal. The third best team in the playoffs and they’re likely to go home in Round 1. I’m also kinda stunned at how done the Mavericks look.


The last part is to fire up the math, calculate win probabilities, and feed it to my model. I am not posting the whole thing here, but I will give it to you in picture form.

This is the generic version. I made some tweaks to mine.

Now, I just need to go off and make all the playoff metrics work in 12 hours.

-Arturo

One Comment

  1. Kyle S
    June 8
    Reply

    Glad I finally (re)found your site (kept wondering where you were over at BSG) Was dying to see some playoff numbers like this.

    Thanks and hope you can keep it up!

    Kyle

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