Nylon Calculus: Blowouts are the new normal in the Conference Finals

The 2018 Conference Finals have been defined by blowouts. Going into last night’s Game 4 between the Rockets and Warriors, only one of the seven games had been decided by fewer than 10 points. We’ve also seen four games decided by more than 20 and two games decided by more than 40 points.

It’s unusual, to say the least.

Since 2014, ten games (out of 49) in the Conference Finals have had a winning margin of more than 30 points. From 1991 to 2013, just six Conference Finals games (out of 266) ended with a margin of 30 points or above. The chart below shows histograms of the margin of victory in every Conference Finals game since 1991:

Massive blowouts in the Conference Finals used to be rare enough that we could remember every single one — the Seattle SuperSonics ran the Utah Jazz out of the building in Game 1 of the Western Conference Finals in 1996. The Jazz won a crucial Game 6 by 35 points to force a Game 7 (which they lost by four).

The same year, Chicago Bulls set the tone for their sweep of the Orlando Magic in the Eastern Conference Finals by winning the first game by 38 points. The next major blowout was in 1998, when the Utah Jazz gave the business to the younger Los Angeles Lakers in Game 1 of the Western Conference Finals, which turned out to be a sweep.

In the 2000’s, only two Conference Finals games were major blowouts: in 2001 and 2008. Both involved the Los Angeles Lakers winning against the San Antonio Spurs, albeit with vastly different teams. Only three players played in both games — Derek Fisher, Kobe Bryant and Tim Duncan.

But recently, we have witnessed explosive development in the number of blowouts in the Conference Finals. As seen in the graph above, Monday night’s Cleveland win over Boston was the first game this year within 10 points (The Cavaliers won by nine). Last season only two games in the Conference Finals were within 10 points. Compare that to 1996, with the three games mentioned above, where four of the seven games in the WCF were decided by four points.

Overall, the resulting average winning margin has risen in the last few years:

One possible explanation could be that the 3-point rate has gone up. More 3-pointers could mean more blowouts, when some teams get hot and others go cold. But the relationship between blowouts and 3s is not crystal clear when we look at the data. As can be seen above the three-point rate rose in the 1990’s and 2000’s without the average winning margin rising.

Next: The Warriors and Rockets are hunting mismatches

The blowouts of the last few seasons coincide with the 3-point rate rising to an even higher level, but that might be a coincidence. Other explanations could be that teams are better at maintaining leads or we have been in a very particular situation with regards to the best teams in the conference. Cleveland and Golden State are responsible for six and three of the recent ten 30+ point wins since 2014 in the Conference Finals. So the many blowouts might just be an indication of their dominance and the lack of opposition.