Saying that the Cavs defense improved this season only says so much. Last year, under Byron Scott, the Cavs defenders seemed to lack any sort of objective or plan, and just kind of wandered around.
Mike Brown was then brought in, mostly based on his defensive reputation. The task was not easy. In the 2012-2013 season, the Cavaliers allowed a league worst opponent field goal percentage of 47.6%. They allowed 106.9 points per 100 possessions, good for 25th in the league. In 2011-2012, the numbers weren't much better: 46.7% FG (26th) and 106.0 Points per 100 possessions (also 26th). The continued defensive failures are a big part of why Byron Scott lost his job.
The defensive improvement most nights this season was visible. There was a clear plan of action, which is deny the paint, and a structure to how things are to be done. Lazy efforts still happened, but less than before. There is also improvement evident on paper. The Cavs finished the season 12th in opponent field goal percentage, allowing 45.2%. They finished 17th in defensive rating, at 104.8 points per 100 possessions. After the All Star Break, the Cavaliers were 7th in opponent FG% at 44.2%, and 11th in D Rating at 104.3 points per 100 possessions.
Mike Brown's system clearly works. Other than Luol Deng for half the season, the Cavs don't have any particularly strong defenders, and that might be kind phrasing. While Dion Waiters, Kyrie Irving, Tristan Thompson, and Tyler Zeller have some defensive POTENTIAL, most nights they are not living up to it, to varying degrees. Alonzo Gee, Spencer Hawes, and Jarrett Jack are not veterans with any sort of defensive reputation. Andrew Bynum was quite possibly the worst player in the league (more on that soon) on both offense and defense. This was a pile of average to bad defenders and an injured Luol Deng, and they ended up being a solid group. After the All-Star break, they were even good.
As we head into the offseason wondering how the Cavaliers can improve on that, we must first identify what the Cavs are attempting to force their opponents to do. As I mentioned above, the system Mike Brown employs values denying the opponent driving lanes to the paint above anything else. The data reflects this as well. The Cavaliers allowed a 4th best 1,969 attempts in the restricted area. How important is that number? Well, the league's three best teams in terms of defensive rating are also the leagues three best teams in terms of number of made field goals allowed in the restricted area. Unfortunately the Cavaliers allow 62.7% of the opponents shots to be made in the restricted area. Even a marginal decrease in that number would vastly improve things.
When you steer opponents away from the paint, they have to go somewhere. The objective for the Cavs is to get their opponents to take as many contested jump shots as possible. The Pacers and Bulls are again a good measuring stick, allowing (or forcing) the most mid range attempts in the league. The Cavaliers are 11th on this list, and 12th in defending said shots.
Unfortunately, we now move on to the Achilles heel, three point attempts. The Cavaliers were miserable, MISERABLE in denying threes. Above the break they allowed the most attempts and makes in the league, despite an average conversion rate of 35.7%. In the left corner they were 29th in attempts and percentage, allowing 43.8% of their opponents 297 attempts to be made. In the right corner they were a little better, seemingly by luck. They allowed a 26th worst 257 attempts but at a 7th best 36.7% completion rate.
What does that tell us? How can we fix it?
Studying the data above, two roster flaws that we already knew about become readily apparent. First, the Cavs lack a player that defends the rim at high level. Second, a smallish and young guard/wing rotation is failing to rotate and contest three point shots. The former is more important, and even somewhat damaging to the latter. For the most part none of the Cavaliers bigs had a very good season defending the post in isolation, so to deny paint looks the Cavaliers began sinking a guard to try to crowd or double many post players. In a vacuum, that is a good decision, and probably is the right call regardless.
For the Cavs, this becomes a major problem. With the exception of Luol Deng and Earl Clark, the Cavs guards and wings Kyrie Irving (6'3), Jarrett Jack (6'3), Dion Waiters (6'4), Matthew Dellavedova (6'4), Cj Miles (6'6) and Alonzo Gee (6'6) are a smallish group by NBA standards. Alone, that is not a huge issue, but combined with the fact that most of them were not particularly good when rotating on defense, the Cavs got picked apart from behind the arc. When you run three guard sets, and don't have a size advantage like you might find in Indiana, Memphis, Golden State, or Miami, it removes your margins for error on help defense.
This first need is glaringly obvious. The Cavs absolutely MUST find someone to block shots and defend the rim. Anthony Bennett, Thompson, Varejao, Hawes, and Zeller simply cannot be the rotation for next year if the Cavs hope to be built on defense without serious development. I don't know who would go, or who would stay, but we have pretty conclusive evidence that barring some sort of unexpected improvement this group is not functional on the defensive interior. Being able to erase points when your guards get beat, and not needing to pull them down to crowd post players is a massive help. When you look at top defenses, it is not a shock to see the teams that employ Roy Hibbert, Joakim Noah, DeAndre Jordan, Tim Duncan, Marc Gasol, and Andrew Bogut.
The second need is a bit murkier. Luol Deng and CJ Miles are free agents. Alonzo Gee and Matthew Dellavedova are on unguaranteed salaries. The Cavs desperately need to infuse their wings with some size and athleticism to cut down on open threes and force the opponent to step in for more mid range jumpers. Sure, having solid post defenders they can trust in isolation helps, but the margin of error is so much greater with taller/longer defenders. As evidence, I suggest you read this wonderful piece on James Johnson (who happens to be UFA this year). If you're going to force guys out to the perimeter, doesn't it make sense to be able to contest their shots?
The insanity of the offseason should be setting in soon. Hopefully there will soon be a plan too. This year the Cavs were passable on D, despite being at a constant disadvantage. With a few tweaks hopefully they can turn the tables a little bit.