This has mostly been due to a sort of backlash against John Hollinger's primary use of this statistic in order to make predictions regarding team success. In this space we have certainly pushed back against such a primary use of point differential. But again, there's a "but'' …
We want to take a moment to explore some of the truth behind point differential as a helpful indicator. Coach Rick Carlisle himself has recently stated that point differential is "an indicator of the overall strength of your game."
Carlisle's full quote on the subject: "Last year we had a great record during the regular season, but we had a poor point differential. We had the eighth-best point differential in the West, and that's an indicator of the overall strength of your game. Our goal this year is to have a better differential. How do we get there? Better defense. What does that mean? It means that we've acquired some guys who we feel are better defenders that can help us in that area. We made improvement last year, and if we're better this year personnel wise there's no reason we can't continue to move forward in that direction."
Now let's get this straight: We still thoroughly believe that those like Hollinger are misguided when they fail to see point differential as only "an indicator" and give it too much weight as "the indicator." That position has not changed. And in fact, we have always considered point differential something that should be considered when one is reflecting on the strength of one's team.
Let's start by looking at the Mavericks own performance in point differential as compared to playoff success over the last decade.
Mavericks Pt Diff WC Rank Result
2009-2010 +2.7 8 Lost 1st Round
2008-2009 +2.0 7 Lost 2nd Round
2007-2008 +4.5 7 Lost 1st Round
2006-2007 +7.2 3 Lost 1st Round
2005-2006 +6.1 2 Lost Finals
2004-2005 +5.7 3 Lost 2nd Round
2003-2004 +4.4 4 Lost 1st Round
2002-2003 +7.8 1 Lost WC Finals
2001-2002 +4.2 4 Lost 2nd Round
2000-2001 +4.3 4 Lost 2nd Round
We see that the two times the Mavs advanced beyond the second round of the playoffs (2003 and 2006) were the only two times the Mavs had a point differential in the top two in the West. The two times the Mavs were third in the West, they had one first-round exit and one second-round exit. The three times the Mavs were fourth in the West, they had one first-round exit and two second-round exits. The last three years the Mavs have had the three worst point differential ranks of the last decade and have been ousted in the first-round twice and the second round once.
Let's now look at the rest of the Western Conference over the same time period. What were the point differential ranks of the two teams in the Western Conference Finals?
WC Finals Win Team WC PD Rank Los. Team WC PD Rank
2009-2010 Lakers 4 Suns 3
2008-2009 Lakers 1 Nuggets 5
2007-2008 Lakers 1 Spurs 5
2006-2007 Spurs 1 Jazz 5
2005-2006 Mavs 2 Suns 3
2004-2005 Spurs 1 Suns 2
2003-2004 Lakers 5 Wolves 2
2002-2003 Spurs 3 Mavs 1
2001-2002 Lakers 2 Kings 1
2000-2001 Lakers 6 Spurs 1
Avg 2.6 Avg 2.8
We see some interesting things here. In seven of the last 10 years the No. 1-ranked point differential team made it to the WC Finals. Only once (last year) did neither of the two top-ranked point differential teams make it to the WC Finals. Strangely, four times in the last decade the fifth-ranked team has found itself in the WC Finals (the same number as the second-ranked team). The only team ranked fourth or lower to advance to the NBA Finals out of the Western Conference has been the Lakers—three different times over the last decade (which in our minds is more of a credit to Phil Jackson and his coaching ability than to Kobe or Shaq).
Looking at point differential and playoff success over the last decade in the Western Conference we see that there is definitely a correlation. If your team is not ranked in the top five in point differential there is very little chance that they will advance to the WC Finals (1 in 20 according to the last decade). And beyond that, being in the top three is the most important because those teams have filled 14 of the 20 WC Finals appearances over the last decade.
In regard to the Mavs' own history over the last decade it has been imperative for them to be in the top two in order to advance to the WC Finals.
Very few teams (seemingly only the Kobe/Shaq Lakers) are able to coast through the regular season (barely beating the teams they play) and then turn it on in the playoffs. So while we still believe that the Mavs' future is not bound to the results of the past -- or necessarily bound completely to point differential – an understanding of it at least gives us some guide for helping us set our expectations.
And just like Carlisle indicated, we should not expect the Mavs to advance far if they do not improve their point differential performance.