Attempting To Explain Warriors' Improvement On Defensive
One of the ways to analyze the defensive changes for this year is to compare it to previous years. While the Golden State Warriors languished in the bottom five of the NBA in defensive efficiency for the past four seasons, they are eleventh in the entire league so far this year. Zach Lowe has already done some strong work on explaining some of the more interesting components of this change a few weeks back and I will try to get into some of the other factors that have made this possible.
In looking at different pieces of information to prepare this piece, one of the more interesting things I found was the changes in where opponents are shooting against the Warriors this season. Using information from Hoopdata, I ran some comparisons between where the Warriors’ opponents shot the ball thus far in 2012-13 compared with both last season and the last full season they played (2010-11). Hoopdata separates the distances into five categories: At the Rim, 3-9 feet, 10-15 feet, 16-23 feet, and three-pointers. With one exception I will get into later, there are two big goals when it comes to defense on these lines: have players take shots from longer distances and/or have them make a smaller amount of the shots from a given distance.
One thing to note before getting too deep into this analysis: some of the total figures for this season are affected by the fact that the Warriors are playing almost two possessions per game less this season than they did in 2010-11 due to the team playing at a slower pace. That means there will be less attempts in total to distribute. This year and last year are close enough (their Pace Factor is up a little over one possession per game) to make it a smaller deal.
Starting from the basket, teams are taking one less shot per game at the rim compared with last year and a full two less when looking at 2010-11. Since opponents make over 60 percent of their looks here (the best of any distance), reducing the amount of shots is a very good thing. On top of that, teams are making a smaller percentage of them when compared with 2010-11 and a little bit better than last year, so they are not getting more efficient here either.
Moving out from the rim, we have the bigger stories of this year’s team. Unsurprisingly, the 3-9 foot range often has the next-best success rate (though it varies quite a bit from team to team and season to season). Here, opponents are taking dramatically less shots- 3.6 less per game than either of the previous two seasons. Coupling this with the reduction in rim attempts discussed before, we paint a picture of a Warriors team that makes teams take shots from farther away from the net than previous iterations. This has to be considered a very good step.
However, these is one issue to spot here: opponents are making a higher proportion of their looks here (up 3.6 percent from last year and 2.8 percent from two years ago), which has actually changed the landscape of efficiency for them. This stands as the only season of the three analyzed where the Warriors allowed teams to score better from 3-9 feet than any place other than the rim and the 42 percent that teams shot from here is better than any range other than at the rim over the past three seasons. Interestingly, the amount of these shots that come off assists has increased as well, which could help explain why the efficiency has gone up. Reducing the attempts marks a meaningful and positive change but the team needs to make sure that they do a good job both marginalizing these looks and getting the rebounds when they come.
Moving on, the first true mid-range distance says a few interesting things about the Warriors. At first glance, the fact that teams are shooting less shots from 10-15 feet away (about one less per game compared with both prior seasons) would seem like a good thing. However, it proves to be a harder case since teams have consistently shot the worst from this range over the past few seasons against Golden State. It gets complicated because most other teams give opponents more trouble from deep mid-range than closer mid-range; the Warriors are closer to the exception than the rule, which makes conceptual sense. What makes this so compelling are the teams that fit Golden State’s result here this season: Indiana, Miami, Milwaukee, New Orleans, Orlando, Philadelphia, and Phoenix have forced their opposition to shoot worse from 10-15 feet than 16-23 thus far. Two of these eight teams are in the top eight of the league in defensive efficiency, four in the middle third of the NBA (including the Warriors tied for 11th), and the two worst teams in the league defensively. Without any rhyme or reason in terms of the effectiveness of this pattern, I will leave it be for now. That said, the other big change here is that a much lower proportion of these shots have been assisted this season- almost one-third less of them compared with either of the last two seasons. While not a holy grail of defensive truth, having fewer of these looks come off passes should be construed as a good sign.
If you have been following along closely, you might have noticed that the amount of shots per game decreased in all three of the closer distances. As such, it would follow that as long as the number of attempts is close teams would have to be shooting more from somewhere. This first comes into shape here as teams are taking 1.3 more deep twos than last season and 1.7 more than the last full season. The most fascinating part about this is that they are doing so while also making less of them than before. The 37.6 percent that teams are shooting from this distance is by far the best the Warriors have done the past three seasons and puts them right in the middle of the league as opposed to placing near the bottom previously. Shooting more shots at a place where other teams have been less successful marks a major victory for the Warriors defense.
The most shocking change in shot selection for opponents has to come from the three-point line. While the Warriors hovered around 19.5 threes taken per game for opponents the past two seasons, that number has rocketed to 24 per game so far this year. While that is only the third-most this year (partially because everyone shoots threes against Miami), it would be the highest per-game total of any of the last six seasons. That likely means that there will be some downturn in the numbers for everyone since the league average is a full two attempts per team per game up from the last full season but it still provides a pivotal piece of the puzzle here. There are two other good pieces of news here for Golden State supporters: even though teams are shooting more threes against the Dubs, they are making less of them and dramatically fewer of them are assisted. In 2010-11, 90.5 percent of the threes taken against the Warriors were assisted- this year that is down to 79.6 percent, a gigantic drop. The problem that underlies all this good information is that taking threes is better than taking mid-range shots in terms of expected points since they are worth more. Other than free throws and shots at the rim, threes are typically the next-best shots for teams to take. As such, the uptick has been a negative even as teams are shooting worse from there.
The shift back of opponents’ shots has had one other interesting and massive effect: when teams shoot from farther away the rebounds usually get farther from the basket as well. Moving rebound opportunities from the paint could hurt some teams yet it fits beautifully with Mark Jackson’s emphasis on having the entire team rebound. In each of the last two seasons, Golden State stood dead-last in defensive rebounding. This season, they are #1 in the entire NBA at this point. This change means more than any difference in efficiency discussed above. In 2012-13, the Warriors have taken about 5 percent more of the available rebounds when they are on defense than the past few years. That 5 percent makes a gigantic difference because it not only reduces the amount of possessions opponents get- the second chance ones it takes off the board are many of the toughest to defend since the defense is often out of position and tired at that juncture. Furthermore, having teams shoot from deeper makes it less likely that they will get the type of put-back looks at the bucket that have haunted Warriors teams far too often recently and longer rebounds can help some teams fast break more easily. While I have been critical at times about Jackson’s scheme on offense lacking cohesiveness, all of the components of the defense have worked together incredibly well this season and that gains even more impact when considering that their best defensive player has only been on the floor a sliver of the expected time thus far.
With improved rebounding, scheming, and effort on the defensive end, the Warriors have transitioned into a much more formidable team to score on than any time recently even without Andrew Bogut. That is quite the accomplishment and it can continue to fuel them through some of the off nights the offense will undoubtedly have.