In "Every Play Counts," Kevin Pelton focuses on one player, team or matchup in a single game, looking to explain how and why they succeed or fail. Naturally, one game isn't everything, but the results can be illuminating.
The final question in last week's Basketball Prospectus NBA roundtable--"What NBA storyline isn't getting enough attention right now?"--was a bit silly to the extent that the three of us analysts answering the question are, of course, also in position to rectify the lack of attention we lamented. As a result, the topic for the latest Every Play Counts breakdown comes from Sebastian Pruiti's answer to the storyline flying under the radar: The Dallas Mavericks' zone defense.
"Since zone has been allowed in the league," he wrote, "we haven't seen a team use it as their primary defense (instead, coaches use the zone to switch things up from time to time). Dallas is using the zone and playing very good defense as a result. It will be interesting to see if it can continue."
As pointed out in the comments, there is a precedent for the success the Mavericks have had with the zone defense early this season. We don't have to look far to find it. This same Dallas squad, then coached by Don Nelson, made extensive use of the zone during the 2002-03 season. Initially, the zone was highly effective as the Mavericks got off to a league-best 14-0 start, but teams figured out how to attack it and Dallas' Defensive Rating rose over the course of the season.
That example aside, this year's Mavericks are certainly unusual in their heavy use of the zone defense and their success with it. 12th in the league in Defensive Rating a year ago, Dallas has improved to sixth thus far this season. While the biggest factor in that improvement has been the addition of Tyson Chandler, the zone--with Chandler anchoring it--has also been a major factor.
To get a better sense of what makes the Mavericks' zone work, and how it compares to their man-to-man defense, I broke down tape of Tuesday's game against the Milwaukee Bucks. As it turned out, the hot-shooting Bucks went into the American Airlines Center and ended a 12-game Dallas winning streak. Milwaukee, the league's worst offensive team, exploded for 60 second-half points. The damage was done against both man and zone defenses. I charted the base defense for each possession and its results. The Mavericks allowed 27 points on the 28 possessions they played zone, all but one of them in the second and fourth quarters. In their 52 possessions of man-to-man defense, they allowed 54 points.
Dallas coach Rick Carlisle has been emphatic that he doesn't see the zone as covering up weaknesses in his team's defense, but clearly he is spotting it based on his personnel. The Mavericks used zone almost exclusively when their smaller backup guard duo of Jose Juan Barea and Jason Terry was in the game together. Carlisle also seems to favor having Nowitzki with one of the team's two strong defenders in the middle, Chandler or Brendan Haywood. Put Shawn Marion on the other wing in the zone and Dallas' length in the frontcourt can be imposing for opposing defenses.
If we were to categorize the Mavericks' zone, it would be as a simple 2-3, the most basic form of zone defense that you can see at YMCAs around the country on Tuesday nights. That description fails to do justice to the complexity of what Dallas is running. The Mavericks have incorporated elements of the matchup zone into their defense. What stands out is that defenders venture out of their assigned area far more frequently than in most zones.
This was especially true in the case of matching up with Andrew Bogut. Haywood or Chandler followed him far out to the perimeter rather than passing him off to one of the guards at the top of the zone. Additionally, the Dallas 2-3 is more flexible in terms of providing help defense, with the wing defenders sucking down into the paint on a regular basis to help protect the basket. I also noticed something I can't remember ever seeing in a zone at any level. When the offense was in a 1-4 set with screening actions in the paint, one of the high defenders would actually turn toward the basket in order to be position to cut off any cutter coming off a screen for a shot.
How do opponents beat the Mavericks' zone, then? The best attack would seem to be a classic one against zone defenses: overloading one side of the basketball and then reversing it. When the Dallas defense overcommits, it becomes vulnerable to penetration after one pass across the top of the key. As is typical of zone defenses, the Mavericks can also be beaten on the offensive glass. Consecutive putbacks early in the fourth quarter helped give Milwaukee life.
As for Chandler, it's exciting to see him providing the kind of defensive lift he once did in New Orleans. After back-to-back injury plagued years, it looked like his time as a starter might be past. Instead, Chandler has parlayed a solid summer with the U.S. National Team into an exceptional start. Statistically, Chandler is something of an enigma. His blocked shot rate has never been anything special. In fact, Haywood is blocking shots more frequently this season. Still, when Chandler is healthy, his teams tend to defend much better with him on the floor, and this year's Dallas squad is no exception. That the Mavericks are allowing 5.4 fewer points per 100 possessions with Chandler (per BasketballValue.com) is impressive given that his backup is no slouch. Chandler's size seems to create problems even when he's unable to actually swat away a shot attempt.
The unsung hero of the Mavericks' defense might be Kidd, who was phenomenal one-on-one against John Salmons (who scored five points on 2-of-7 shooting) and even contained Brandon Jennings on the rare occasions the two matched up. Kidd's quickness might be gone, but his intelligence, savvy and strength help make up for that liability. The emergence of DeShawn Stevenson as a viable offensive player has given Dallas another option for cross-matching in the backcourt with Kidd defending shooting guards and Stevenson handling point guards. The versatile Kidd is even playing some small forward alongside Terry and Barea as part of the Mavericks' zone, playing on the back line.
Based on the way Dallas has defended in the first month and a half of the season, combined with the in-depth analysis of Tuesday's game, I don't think the Mavericks are inevitably bound to fall off as teams figure out their zone. Dallas isn't relying on a gimmick so much as it is using the zone to take advantage of its defensive capabilities. Surely, the Mavericks benefit to some extent from opponents' relative unfamiliarity with the zone, but that is unlikely to change any time soon. As long as Chandler stays healthy and continues to lead the defense, Dallas should continue to thrive in both man and zone.
Kevin Pelton is an author of Basketball Prospectus.
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