Virginia basketball thrives with the Pack Line defense. Here’s how it works.

In 2015, the Harvard Crimson won the Ivy League, made the NCAA tournament, and just narrowly lost to North Carolina in the first round. That team won 22 games.

Against Virginia, though, they only scored 27 points.

In the intervening years, we’ve seen the Virginia Cavaliers post no small number of stalwart defensive performances. Just last year, they held Clemson to 36 points, and in the ACC Tournament finals, smothered a high-octane UNC team into a performance 11 points worse than the Heels’ per-100-possession average.

Virginia's rise to the top of the college basketball world has been built on defense, and specifically the Pack Line defense engineered by Tony Bennett's father Dick. Here’s how it works.

The System

Bennett-style defense operates from three philosophical starting points:

1. Deny the fast break
2. Deny the dribble penetration
3. Deny the offensive rebound

The Hoos implement the first point with a conscious decision to get back in transition instead of crashing the offensive glass. But the second and third points are brought about with the Pack Line system.

The Pack Line gets its name from an imaginary line inside which all the off-ball defenders play. It's a man-to-man system with some zone tendencies: If your man has the ball, you're out in his face; if you're off the ball, you track your man as he moves; but every off-ball defender also plays off his man enough to help with the complex system of slides and help defense underneath.

Coachbase

In practicing the Pack Line, the coaches actually tape down that line on the floor.

As the ball swings around the perimeter, the off-ball defender pops out and crashes the new ball-handler. The man who was on-ball then slips back under the line and packs the middle of the defense. (You can hear Coach Bennett emphasizing those floor lines in the video from which that image was taken.)

Coachbase

If the ball goes into the post, Bennett's defenses will frequently crash two bigs down for a quick post double. If a post player comes out to set a pick for a ball-handler, the big comes out and hedges HARD while the on-ball defender hustles around the pick; one of the other off-ball defenders slides into space to catch the pick man as he comes back in, shutting down the pick-and-roll.

Coachbase

The result of that aggressive help defense can be ... impressive.

(One thing to note that's actually a breakdown in that video: in the first clip, Joe Harris lets his man break toward the baseline, a huge no-no in Bennett's system. While most defenses do try to force toward the baseline and use out-of-bounds as a sixth defender, Pack Line defenses want to force the ball toward the middle, since that's where the help is. Three of Joe's teammates bail him out there, but dollars to doughnuts that was discussed in film session after the game.)

With all four off-ball defenders packed in under that imaginary line, there are four bodies close to the hoop to snare any errant shot. Virginia's phenomenal defensive rebounding does require grit and individual technique, of course. But it's helped by the system that puts each player individually in a position for the team to rebound collectively.

When it's working well, the five defenders on the floor operate as if they're tied together with a string. Rick Pitino compared it to five fingers coming together to make a fist after Virginia beat his Louisville team during the 2015 regular season (a feat that UVA has gone on to repeat ... a lot). The people who complain about the Hoos' suffocating defense being boring don't understand the complexity of what they're watching.

The Personnel

So who does it take to make this complicated, constantly moving defense work as it’s supposed to?

The two signature elements of the defense are the post double and the hard hedge at the top of the key. As a result, you’ve got to have agile big men who can fly around the court. Of the three Cavaliers to win ACC Defensive Player of the Year in the past five seasons (!!), Darion Atkins and Isaiah Wilkins were both bigs who fit this mold to a T.

Jack Salt has grown into a taller version of that over the past few seasons. While no one will confuse the Killer Kiwi with a prima ballerina, Salt’s footwork has definitely improved on the hedges since he arrived on Grounds. His 7-foot frame also makes for an effective impediment to passes into the post as he drops back after the hedge.

Mamadi Diakite has what one would consider the more prototypical frame and athleticism for a hedging, doubling post player. If Jay Huff can stay healthy and show Bennett that he’s developed the defensive awareness to hold his own, UVA should have three players in 2018 who can contribute major minutes in this role.

Because so much of the Pack Line operates off of spacing and off-ball rotation, attributes you’d look for in zone defenders are strong pluses for Pack Line defenders, too: length to shut down passing lanes and to take up space as help rotates in.

Here’s a sample of the guard and wing sizes for Virginia in 2018:

• Marco Anthony: 6-foot-4
• Ty Jerome: 6-foot-5
• De’Andre Hunter: 6-foot-7
• Kody Stattman: 6-foot-7
• Francesco Badocchi: 6-foot-7
• Braxton Key: 6-foot-8

Bennett has prioritized getting long athletes into Charlottesville, because it makes his great defense downright scary.

The Weaknesses

There are a few vulnerabilities in running the Pack Line. A ball-handler who can routinely beat his man off the dribble creates huge problems if he can also make good passes: as the off-ball defenders come to help the dribble penetration, they leave passing outlets open. The same goes for post players who can pass quickly and accurately out of double teams (or even before the double team arrives). Strong perimeter shooting teams can also have success since defenders are two or three feet under the three-point line; a quick release is extra difficult for the Pack Line to stop.

The Pack Line may never work in the NBA since a professional team can put all three types of those players—the elite ball-handler, the passing big man, and the quick-shooting wing—on the floor at the same time. Most college teams, however, can’t.

But most of Virginia’s truly inexplicable losses in the Bennett era have come against teams with two of the three elements above. Jitterbug guards like Miami’s Chris Lykes routinely give the Hoos fits. And of course, in That Game, the combination of a 5-foot-8 point guard and a team that shot 50 percent from three buried UVA’s Final Four aspirations.

And give Bennett credit for recognizing and trying to address the weaknesses in his system, especially the fleet-footed guard problem. Virginia went hard to land Lykes out of DC’s Gonzaga. Freshman guard Kihei Clark—all 5-foot-9 of him—has brought a tenacious defensive approach to Charlottesville: he got under Jerome’s skin badly enough that the junior standout threw a ball at Clark’s head.

No defense is flawless. Any team can have breakdowns in communication or lapses in effort. But the Tony Bennett-led Cavaliers have put together years with as close to a perfect defense as you’re likely to see in college basketball. And it’s the Pack Line that helps them do it.

(For a detailed video breakdown, including coaching pointers, check out this great video from Coachbase.)