Grading how NBA players do on defense is a very subtle art.
As a team, the Bulls' defense has been a lot better than people (including me) thought it would be. As KC Johnson tweeted, the team is holding opponents to the lowest FG% in the league and is 5th in Defensive Rating.
To find out how the guys are doing on a player-by-player basis though, we need to stop trying to rely on advanced stats and start focusing more on eye test.
Individual defensive advanced stats lag way behind offensive ones - defensive sieves like Carlos Boozer (5th in Defensive Win Shares in 2012) and Pau Gasol (8th in Defensive Rating this year) show up on the leaderboards all the time. To judge a player's defense, pulling random stats is oftentimes not useful.
The best method we have right now to judge defensive ability is the eye test, and more specifically watching how guys do off the ball. Oftentimes a shot is scored or a rebound is secured because of a breakdown earlier in a possession away from the ball.
There are dozens of things to look for on every play. Using last night's Bulls-Pacers game as an example, here is a small sample of some of those things.
Example 1 - Allowing Offensive Rebounds
A great example of poor off-ball defense is when other teams secure offensive rebounds because of a failure to box out. Derrick Rose and Doug McDermott are two of the worst offenders when it comes to this form of defense - making sure a rebound is secured.
Here's an example from last night. Rose falls asleep on defense and lets his man, Monta Ellis, run completely past him to secure an easy rebound and putback:
Jimmy Butler has even joked with the press about how bad a team rebounder Rose is, telling them after the Magic game two weeks ago, "Hell, [Rose] had some rebounds tonight. I was talking to him on the bench, my man was in there rebounding."
McDermott is also poor at boxing out. Despite being 6' 8", he oftentimes gets outmuscled in the paint and lets his man get multiple second chances for the opposing team.
People don't want to hear it, but Hinrich is great at helping on team rebounding by boxing out. He doesn't back down from boxing out centers and finds a body to box when the shot goes up.
Example 2 - Ability to Fight Through Screens
Another huge facet of being either a great defender or a poor one is one's ability to fight through screens.
What makes Jimmy Butler a tremendous off-ball defender is that he is very difficult to screen. He will use multiple efforts on one possession to blow up plays designed for his man and force offenses to go to a second or third option instead.
This is a set play, a sidelines out of bounds play, that the Pacers tried to run for Paul George last night. The play didn't work because Jimmy Butler fought through the initial screen and George had to catch the ball way out on the perimeter. The second option didn't work either because again, Butler fought through another screen.
The Pacers had to settle for their 3rd option, which was a weak-side screen on Mirotic to set up a 3. The Pacers ended up hitting that 3 because Mirotic couldn't get through a weak Chase Budinger screen nearly as well as Butler got through his screens.
Another great example was on the Pacers' last possession of the game. Frank Vogel drew up a double screen for Paul George and Butler got around both picks easily. Butler's block is what people will be focusing on, which of course was excellent as well, but Butler isn't in position to make that play if he isn't also great at getting around those initial two screens.
Example 3 - Not Overhelping off the Ball
Arguably the most important part of being a good team defender is knowing and understanding body positioning. Young players like Nikola Mirotic oftentimes have trouble with this aspect - Mirotic has a tendency to overhelp and leave his man too far, as Stacey King illustrated on the Bulls' broadcast last night.
One way good veteran defenders are able to balance helping on the ball while remaining in good position is by stunting, which the old school Thibs Bulls were great at. Zach Lowe once broke down Thibodeau's defense for Grantland and noted,
Chicago is also probably the best team in the league at stunting — that is, having a wing defender fake aggressive help in the middle of the floor with no intention of actually staying there.
As their personnel has changed, the Bulls have gone away from this strength. However, Hinrich and Butler are still two of the best at this - they offer help without compromising their defense on their man:
Butler and Hinrich are both able to fake as if they are giving help on the ball while staying in position to guard their man if a pass comes out. Butler is also great at getting his hands up in the passing line, akin to an NFL pass rusher, to make life really hard on the ballhandler if he tries to pass.
There's a really delicate balance here too between faking help while giving yourself room to recover versus over-committing to help, as Tony Snell illustrates here.
All of these defensive evaluations are not even getting into pick and roll defense, which is an even more complicated beast that deserves its own separate space.
The takeaway point is this: If you are wondering if player X is a good or bad defender, watch only him for a couple of possessions, even when he is off the ball. You'll be amazed at how much you can tell in a five-minute span on the good and bad things that you see.