Road wins are never easy. Last Wednesday in Maples Pavilion facing Stanford, things were particularly difficult for the then No. 1 Arizona Wildcats, because the shots just weren't falling.
But the Wildcats prevailed, protecting their unbeaten record by holding the Cardinal offense to 0.88 points per possession. Later in the week, the Wildcats lost their first game of the season, but even in that loss the defense was still excellent. Arizona's 21-1 record owes a lot to its stifling D.
Using Ken Pomeroy's adjusted defense rating, Sean Miller's squad is the best defense in Division I. In Pac-12 games so far, the Wildcats are holding opponents to 0.87 points per possession; the second best team is UCLA, which allows 0.96 points per trip.
There is no one single factor that makes a defense this good. It takes a combination of things. Arizona rebounds well, doesn't foul and forces the occasional turnover. These things all matter. But the central characteristic of Miller's defense is that it makes opponents work hard to get good shots.
Limiting good shots
Arizona opponents have the lowest effective field goal percentage in the country at 42 percent. The Wildcats accomplish this by forcing opponents to take a majority of their shots from mid-range. Per the Hoop-Math.com defensive leaderboard, Arizona allows the lowest percentage of opponent attempts in the rim nationally. No team makes its opponent shoot a higher percentage of its attempts on two-point jump shots than do the Wildcats.
This is important. Across college basketball, about 37 percent of all shot attempts occur at the rim, and 33 percent are from beyond the arc. These shots -- along with free throws -- are the best sorts of shots that a team can take. Shots at the rim on average go in around 60 percent of the time. Three-point attempts tend to fall around 34 percent of the time, but because three-point shots are worth an extra point they provide an effective field goal percentage of 51 percent.
The remaining 30 percent of shot attempts in college hoops are two-point jump shots. These shots fall across the country around 35 percent of the time. This is no man's land for an offense.
If we delve more deeply into the shot distribution of Arizona opponents, we get a better feel for what exactly makes Miller's D so effective. The table below shows where Arizona opponents have gotten their shot attempts so far this season. Wildcat opponents rarely get to the rim, and shoot far fewer threes than average.
Arizona opponents' shot distribution (hoop-math.com)
The Arizona D gets particularly stingy in the half-court, where opponents end up shooting two-point jumpers on 58 percent of their attempts; in half-court situations Wildcat opponents have only managed an effective field goal percentage of 39 percent.
Breaking down Arizona's half court defense
The series of images below taken from a single possession of last week's win over Stanford help us understand just how Arizona manages to both cut off the rim and limit outside looks for dangerous shooters. Stringing together enough possessions like the one below leads to defensive excellence.
In this possession, the ball starts off on the far wing. Josh Huestis is the man with the ball. In this play, the ball will reverse to the near-side wing, and Huestis will run off of a screen to try to get open for a shot or drive to the basket.
I want to draw attention to where each of the defenders are in the play. In the image above, if the ball handler makes a penetrating move toward the middle of the floor, he will find himself in a crowd of defenders, as three Wildcats currently occupy positions to limit penetration into the paint.
Huestis passes the ball to Dwight Powell (No. 33), who has popped out to the top of the key, as shown in the image below. His intention is to reverse the ball and then set a screen.
I want to draw attention to the way that Arizona is choosing to defend Anthony Brown in the far corner. Brown is two passes away from the ball. In this position, a common man-to-man tactic is for the defender to drop off his man into help-side position, defending the basket. But Brown's defender isn't doing this. The defense is shadowing Brown, which looks to be a sound strategic bet made by Miller's staff.
Brown is an outstanding shooter who has made nearly half of his three-point attempts this season. I am fond of using a statistic I call Points Above Median (PAM), which measures how many "extra" points a player scores relative to the number of shots he takes. A player with a large PAM total improves his team's points per shot attempt more than a player with a small PAM value. Brown came into the game against Arizona with 33.5 points above median from three-point range. Brown's three-point shooting is the single most efficient way Stanford has to score. The Wildcat game plan was to limit Brown's chances. Anthony Brown was 1-of-3 from long distance in this game, good for a PAM of 0.1.
In the next image (below) the ball has reversed to the near-side wing, while Powell prepares to set a screen for Huestis. Cardinal center Stefan Nastic is preparing to flash across the paint and post up on the near-side block. (He will end up getting in the way of the offense.) Note that Brown is still being guarded closely even though he is now three passes away from the ball, while Huestis' defender has dropped back toward the paint to clog things up. He is joined in the paint by Wildcats Kaleb Tarczewski and Aaron Gordon, who combine to make dribble penetration from the wing an unappealing option for Stanford. Multiple players occupying the paint is a hallmark of Miller's approach to defense.
One thing to keep in mind about the Arizona defense is that for the most part the Wildcats do not challenge these perimeter passes in the way that a team like Duke or Kansas State does. Miller is mostly content to allow opponents to pass the ball around the perimeter in exchange for making penetration into the center of the defense difficult.
The next image (below) reveals the moment of truth. Huestis comes off the screen, while his defender chases him over the top, which will make a three-point attempt for Huestis difficult to obtain. Instead, Hustis curls off the screen. It is the proper read, but it leads him right into trouble. Gordon and Tarczewski are ready, clogging up the paint.
When Huestis receives the ball, he finds himself with no good options for penetrating and getting to the basket. Arizona has completely cut off all chances to get to the basket. Hustis' defender has nearly recovered after fighting through the screen, while Gordon and Tarczewski have already shut down the driving lane. The near-side ball defender has also collapsed down for good measure, although he should be able to recover to his man, who is only a few feet away, if needed.
The possession ends as Hustis takes a difficult two-point jumper from the position shown above. Arizona boxes out, and Gordon secures the rebound.
There is nothing fancy about how the Wildcats defense works. But nothing fancy is needed.
The Arizona Wildcats D makes life difficult for opponents. Miller's team cuts off the rim, taking away most opportunities for penetration, while simultaneously limiting clean looks for good shooters from three; the Wildcats are perhaps the best team in the country at achieving these two sometimes conflicting goals. To make this happen consistently, every defender needs to be on the same page. The interior defenders work together to help limit dribble penetration that get all the way to the basket, while perimeter players shadow dangerous shooters.