I decided to look into the inner workings of the Bulls defense and how it compares to defensive strategies across the league... because that's what Bulls fans do at work. Thanks in large part to the writings of Zach Lowe over at Grantland, the excellent work of Kelly Scaletta at Bleacher Report and pieces on Blogabull as well as the few tidbits that the notoriously disingenuous Thibs and his players spat out, I was able to cover quite a bit of ground.
The NBA is a copycat league. Yes, it is a cliché, but it is true. I wasn't alive to see the first several decades of the NBA, but from the Jordan Rules paving the way for (ie. forcing the use of) the triangle offense, or the legalization of zones and successful three point shooting offenses (thank you, Rudy Tomjanovich) starting the ascent of outside shooting, whatever is successful quickly spreads, teams adjust, and as a result, the league evolves.
We have heard many times that Tom Thibodeau is the pioneer of modern NBA defenses, and though the Bulls defense slipped a bit last year thanks in large part to injuries, there is no doubt that Thibs' opponent-specific, meticulously designed schemes are the cream of the crop.
Relying on locking down the interior, using the sidelines and baseline as additional defenders, yielding only the lowest efficiency shots, and a complicated zone/man-to-man hybrid help system, offenses around the league were brought to a standstill. Teams ran into, fundamentally, the same defense quite often, and offenses have begun to adjust (I highly recommend reading this piece) by using tons of decoy action, weak side activity and ball reversal, often using post ups and drives only to draw defenders and kick the ball out to give the "real" offense a head-start. Somewhat fits the Bulls' scheme, but they prefer forcing the much riskier cross-court passes.
On Lu & Taj: As the NBA offenses continue to become more complicated with more and more misdirection and decoy action, defenses are challenged to identify the actual play and defend it. Sound simple, but it is a dilemma: surrender a tougher shot to a highly skilled decoy (outside shots in the case of players like Ray or Korver) or risk a deadlier mismatch? Furthermore, the amount of decoy action is highly variable even within the same game, as we've seen from the Rivers-led Celtics. The key is being able to switch on as many of these as possible.
Like everything else scheme related, it is easier said than done. You need the personnel to do it, and very specific types. We already know that the Bulls defense works best with mobile, athletic, fairly large forwards and bigs. Jimmy fits this criteria. The Bulls drafted Tony Snell for the same reason and when he gets strong enough to guard 3s and smaller 4s, he will fit right in.
The Bulls have the premium of having bigs who can switch out on perimeter players. Here, Taj does an excellent job of guarding Carmelo with his quick feet and incredible length. In the first sequence, Deng simply switches onto a dangerous pick and pop player in Novak, essentially ending all opportunities created out of the pick. While Hibbert and Duncan were on the bench because of their inability to guard on the perimeter (and ultimately their teams lost), Taj was chasing Ray Allen around screens in crunch time. Taj was injured a lot, and perhaps didn't show us as much as we'd like offensively, but he is a god in terms of advanced stats, is an integral player on this team and will continue to be that in the future.
It is essential that the Bulls retain Deng for the same reason. A lineup with Noah/Taj/Deng/Butler/Rose gives countless options to switch. Obviously, a high 1-4/5 pick and roll switch will not take place with a good PF/C, but all the floppy action on the wings (decoy or not) will be negated with Rose being able to guard 1's and 2's, Jimmy/Lu/Taj guarding 1-4s in many cases, and Joakim willing to switch to the perimeter even at the All Star game (fuck Chris Paul btw).
Simply put, with the right personnel like Noah, Taj, Jimmy and Lu, switching counters a lot of offensive action in the NBA at a time when the league as a whole is trying to outsmart Thibodeau's defenses. The Bulls need to pay Lu to keep him around, and not trade Taj for crap. Of course, I still haven't started on Lu's value as a two way player who helps you win playoff games, and if Snell progresses well it will give the Bulls one of the strongest two-way wing rotations in the league.