Opening Tip: Monta Ellis a minus for Mavs?

DALLAS -- The data seems damning for Mavericks guard Monta Ellis at first glance.

The presence of Dirk Nowitzki, Dallas’ lone All-Star, has a major positive impact on the plus-minus of every single player in the Mavs’ rotation. The numbers indicate that Ellis, who is averaging 19.4 points and 5.9 assists while shooting a respectable 46.0 percent from the floor, has the opposite effect despite his impressive individual numbers.

Just the stats, using net ratings (points per 100 possessions):

Dirk Nowitzki

With Ellis: plus-1.8

Without Ellis: plus-9.9

Shawn Marion

With Ellis: minus-1.1

Without Ellis: minus-0.8

Jose Calderon

With Ellis: minus-0.7

Without Ellis: plus-13.1

Samuel Dalembert

With Ellis: minus-0.5

Without Ellis: plus-12.4

Vince Carter

With Ellis: minus-4.3

Without Ellis: plus-3.2

DeJuan Blair

With Ellis: plus-0.4

Without Ellis: plus-5.0

Brandan Wright

With Ellis: minus-1.9

Without Ellis: plus-12.2

Jae Crowder

With Ellis: plus-8.4

Without Ellis: plus-10.2

Shane Larkin

With Ellis: minus-0.9

Without Ellis: plus-10.8

Devin Harris

With Ellis: minus-16.7

Without Ellis: plus-13.1

What do the Mavs make of those numbers? Essentially, they see them as confirming the obvious about Nowitzki’s value to the Mavs, rather than revealing anything negative about Ellis.

“We’re really asking [Ellis] to play in some of the most difficult circumstances,” coach Rick Carlisle said.

In other words, almost all of Ellis’ minutes come against the opponent’s starters or when Nowitzki is not on the court.

The Mavs’ rotation is designed to limit the wear and tear on the 35-year-old Nowitzki as much as possible despite him being Dallas’ focal point. Nowitzki routinely rests midway through the first and third quarters, coming out of the game much earlier than most stars. He checks back in three or four minutes later, when Ellis usually gets a breather.

Carlisle never wants Ellis and Nowitzki both on the bench for meaningful minutes. That means the vast majority of Ellis’ time being paired with Nowitzki, whether it’s starting halves or closing games, is against the opponents’ best players. Ellis -- and Marion, whose two-man lineup numbers have a similar trend -- rarely are on the floor with Nowitzki against reserves.

That, the Mavs believe, explains why Nowitzki’s net rating is so much better without Ellis. The Mavs feast when their 12-time All-Star is on the floor against second units.

Sixth man Carter has such a poor net rating when paired with Ellis in large part because most of their time together comes during the toughest minutes for the Mavs. Those are the stints of three or four minutes in every first and third quarter when Nowitzki sits while the opponents’ stars are still on the floor.

“The challenge is non-Dirk lineups. Not Monta lineups,” Mavs owner/analytics pioneer Mark Cuban said via email.

The Mavs other massive challenge, of course, is finding a way to stop opponents from lighting up the scoreboard. And it should be noted that it tends to be especially difficult with Ellis on the court.

For instance, the Mavs allow 107.4 points per 100 possessions when Nowitzki and Ellis play together. Only the Utah Jazz (107.5) have a worse overall defensive rating this season. But that figure drops to 98.1 when Nowitzki plays without Ellis, a defensive rating that would rank third in the league.

The only players whose defensive ratings are worse without Ellis than with him are Calderon and Marion, and those are small sample sizes of fewer than 100 minutes.

It stands to reason that Ellis’ defensive woes are a factor in this two-man lineup phenomenon. Just not nearly as much of a factor as the Dirk dynamic, which is why the Dallas decision-makers defend Ellis.