What are the odds? Team-by-team playoff chances

Originally Published: April 20, 2007
By John Hollinger | ESPN Insider
You want to know why it was such a big deal that the Bulls lost to New Jersey on Wednesday night? I'll tell you why: It cut their chances of making the conference finals in half.

How do I know this? Because I created a model of the NBA playoffs that calculated each team's odds to advance through the four rounds of the postseason. And based on this model, the impact of that one regular-season game is looking positively enormous.

I'll get to the nitty-gritty in a minute, but let me give you a quick overview. This model's best and worst attribute is the same thing -- it's entirely based on a team's results during the regular season. It doesn't know about injuries, or playoff experience, or any other factors; on the other hand, it doesn't bring any subjective biases to the table that can throw us humans off the scent.

What it does know is that the larger a team's average margin of victory the more games it is likely to win, and that's as true in the playoffs as it is in the regular season. Additionally, we know that teams that play well late in the season tend to fare a little better in the postseason.

Fortunately, we have a tool that already combines exactly those two bits of information: the Hollinger Power Rankings.

I used that as the basis to create the chart below, but with one caveat -- I took the rankings through games of April 9, since the final week of the season featured so many games in which teams obviously weren't playing to win. That prevents games like Golden State's blowout of Dallas' scrubs on Tuesday from impacting the model.

Using the difference between each team's rating and a 3.5 point advantage for the home team in each game, we can calculate the odds of a team's winning any individual game. From that, in turn, I built the odds of winning a given series, and eventually of winning the championship.