Coaching Corner — Analyzing The Phoenix Mercury’s Defense » Winsidr

The distinction between possessing great individual defenders and establishing a truly elite defensive team is critical. While an exceptional shot blocker or a tenacious on-ball defender can produce standout moments, such isolated efforts often falter in the absence of a cohesive defensive framework. Effective defenses don’t rely solely on individual skill but on every player’s shared commitment. 

This season, the Phoenix Mercury have exemplified that principle. Their defensive identity is grounded in high ball pressure, meticulous footwork, and disciplined positioning. With an emphasis on disrupting offensive flow at the point of attack and maintaining an active presence in the gaps, they adhere to fundamental tenets of sound defensive basketball. These principles, while straightforward, are neither consistently practiced nor effectively executed by many other teams. The Mercury, however, has turned these basics into the foundation of a unified and highly functional defensive system.

Statistical evidence reinforces the success of this approach. Although they currently allow 79.5 points per game (PPG) — ranking fifth in the league — their overall plus-minus ranks third-best. Their defensive rating and opponents’ three-point shooting are fourth-best. Additionally, the team concedes the third-fewest offensive rebounds per game (RPG) and leads the WNBA in forced turnovers. These metrics highlight the limitations of relying solely on PPG as a barometer for defensive quality, revealing that a team whose defensive impact is both disruptive and sustained across possessions.

The strategic offseason acquisitions largely transformed Phoenix’s defense. The additions of Alyssa Thomas and Satou Sabally through trades, alongside the signings of Sami Whitcomb, Lexi Held, Monique Akoa Makani, and Kalani Brown, have collectively elevated them from a defensively middling team in 2024 to a formidable, championship-contending unit in 2025. Their presence has not only raised the team’s talent level but has also reinforced the collective accountability and cohesion that defines outstanding defensive execution.

Defensive Metric
2024 Phoenix Mercury (Rank)
2025 Phoenix Mercury (Rank)

Opponents’ Points Per 100 Poss
102.9 (9th)
95.8 (4th)

Opponents’ 3PT%
34.2% (7th)
32.1% (4th)

Opponents’ OREB
10.2 (last)
8.2 (3rd)

Opponents’ OREB Rate
28.4% (last)
24.7% (4th)

Opponents’ TOVs Per Game
13.1 (11th)
17.5 (1st)

The chart above illustrates the extent of Phoenix’s transformation, particularly highlighting substantial improvements made by their 2025 unit, and most notably on the defensive end. 

I’ve watched every Mercury defensive possession this season thus far, trying to encapsulate what makes this defense so effective. Here are my takeaways on what’s been a revelatory process in head coach Nate Tibbetts’ sophomore season.

High-Ball Pressure

As mentioned, the high-ball pressure Phoenix plays with is the base of everything they do defensively. Their defenders pick up ball handlers full court, three-fourths, and just after the half-court line. This disrupts the opponent’s rhythm, immediately preventing them from getting into actions and sets. A defender’s quick ball pressure increases the chances of opponents’ offensive mistakes, resulting in errant passes, baseline traps, and easy steals that lead to points for the other team.

In the clip above, you can see Lexi Held immediately pressure Courtney Williams high off the screen. Whatever action Williams wanted to engage Held, nullified it, dashing through the screener and regaining defensive positioning. 

Held pushes Williams further back towards the half-court line. When Williams turned the corner on Held, trying to use Alanna Smith as a screener, Brown hard-hedges by jumping the driving lane and using the baseline as a makeshift defender, a defensive technique known as ICE. The trap forced Williams to turn the ball over.

The second part of the clip demonstrates the same high-ball pressure efficiency. The defense loosely picks up the ball handler three-fourths of the way across the court, then intensifies just as the ball crosses half court. This forces the ball handler to pick up her dribble prematurely, a cardinal sin, but one forced upon her by the high-ball pressure. Sabally, realizing this predicament, jumps the pass to the offensive player for the quick turnover. 

High-ball pressure is designed to disrupt all offensive execution, speeding up the offense to an uncomfortable operational pace. Locked-in defenders will notice the resulting anxiety and exploit it, like Sabally did. They’ll use active hands, stepping in front of passes, and making life miserable for the offensive players.

Help Rotation

Another key aspect of team defense is help rotation. It’s common for a defender to get stuck on a screen, lose a step to an elusive first step by a driving player, or simply lose focus just long enough to get pulled out of the play. That’s where understanding how to play as a team defensively becomes critical. If off-ball defenders are watching and understand their responsibility, they will know when to rotate over to stop a driving ball handler who beats their defensive assignment.

In the clip above, you’ll see a terrific example of Phoenix rotating over to prevent a look at the rim for Seattle. Skylar Diggins initiates the pick-and-roll with Ezi Magbegor, and Mercury defender Sevgi Uzun gets caught on a Magbegor screen. Kathryn Westbeld, Magbegor’s defender, reads Uzun’s placement and switches to cover Diggins until Uzun can recover. Westbeld’s switch gives Magbegor the initial space to roll freely. However, as the pass is made to Magbegor, Thomas, one of the league’s best defenders, sees this and steps up to prevent the easy bucket. Magbegor then has to dribble out and reset the offense. 

Later in the possession, the ball is kicked to the other side for Erica Wheeler. Note the defensive positioning of Held and Westbeld. They’re baiting Wheeler into driving right on her off-hand. As Wheeler drives, Sabally keeps her eyes fixed on her. She slides over and blocks the layup attempt.

Twice in this possession, off-ball Mercury defenders moved perfectly to stop the Storm from scoring.

Pick-and-Roll Defense and Switching

Defending the pick-and-roll requires communication, active feet and hips to rotate as well asan understanding of the offensive players’ tendencies. The level of decision-making is rapid and requires precision; the best defensive teams know how to execute this in real-time.

As the Golden State Valkyries’ Julie Vanloo backs down Held, she initiates the pick-and-roll with Temi Fagbenle. Note Brown’s positioning as she follows Fagbenle into the action. Brown stays square to Vanloo, allowing her to hedge and double Vanloo or position herself to cut off the pass to Fagbenle. As Vanloo passes to the rolling Fagbenele, Brown is in the perfect position to cut off the pass.

There are innumerable examples of Phoenix defending the pick-and-roll successfully. This comes from the connectivity they have as a team, trusting each other to be in the right place. The level of focus and attention to detail, with each person playing a vital role in the team’s success, is what has made the team so good on this side of the ball this season.

Part of this communication is knowing when to switch. In the following clip, note how they seamlessly switch with one another.

The first part of the clip highlights this. The initial ball pressure eases, allowing the ball handler to use the screen and drive. As the original defender trails, Brown stays on the driver’s front hip, moves her feet well, and defends vertically. With the initial defender backing off to avoid a foul, Brown can block the shot cleanly. 

In the second part, Monique Akoa Makani gets caught on an A’ja Wilson screen, forcing a switch that puts Westbeld onto Jackie Young. Normally, this is a matchup Young can easily exploit, but Kiah Stokes’ strong-side positioning naturally cuts off a driving lane. With the taller Westbeld defending, Young is forced to loft a pass higher than usual, too high, resulting in a turnover.

However, Phoenix’s movement and high-energy play neutralize many of those advantages.

Principle of Verticality

Nothing kills a great defensive stop more than a foul. The principle of verticality is a defensive cornerstone for this very reason. It argues that by staying vertical and allowing the ball handler to initiate the contact, it lends itself to fewer fouls being called.

Note in the clip above the way the Phoenix defenders stay vertical through the offensive action. They allow the offensive player to initiate the contact, keeping their hands high and straight, and defending perfectly without drawing a foul against them. 

This is especially challenging in the first part of the clip, when the defender is moving diagonally. That movement can open a defender up to slap at the ball or rotate their hips into the ball handler, but Sabally remains perfectly parallel and vertical to block the shot, and no foul is called.

Trap the Box

Another defensive technique is trapping the box, which goes hand-in-hand with help rotation. Trapping the box is when a defender rotates over from the weak side to the strong side block to defend a shot. 

In the clip above, note how Held rotates herself to Diggins’ strong hand, forcing her to drive right. This is why team connectivity defensively is so critical. Held knows Diggins will drive and see the open lane, but Sabally is on the block, ready to rotate over and cut off the drive. Diggins kicks the ball out wildly, turning the ball over. 

The next part of the clip shows the same. This time, it’s Westbeld who rotates over for the block. Then it’s Kahleah Copper and once more from Westbeld to close the clip. Baiting offenses to drive can be risky, but when defenders are in sync, there’s trust that funneling a player into help will neutralize the threat and lead to a strong defensive stand.

X-Out and Choking the Post

Two other important half-court defensive actions are x-out and choking the post. When the offense moves the ball from low to high, the defense stretches and has to scramble. The weak side defenders switch coverages on the perimeter players, making an X. 

As the Storm drives and kicks to the opposite corner, notice how the Mercury defenders rotate on the weak side to stay connected. Akoa Makani shifts from the weak side wing to the corner, while Westbeld slides over to cover her previous spot. This rotation effectively seals off the weak side perimeter, preventing any clean looks from deep.

Choking the post is, after a post entry, the perimeter defender stunts, or drops to help defend before returning to their assignment. This can cause a quick double team and eliminate an offensive threat in the paint. 

As soon as Malonga received the pass, Held, who was in drop coverage on her assignment, immediately came over to strip the ball from Malonga. It’s a risky gamble, especially against more veteran players who can play out of a double team, but when used wisely, it can result in turnovers.

Stunting

Speaking of stunting, take a look at the clip below for how Phoenix uses stunting to activate defensive chaos. 

As Kelsey Plum drives, watch Sami Whitcomb. Not once but twice, she shifts over to slow Plum down, preventing one of the best dribble drivers in the league from getting to the hoop. The savvy vet swipes at the right time to take the ball away from Plum. This all happens because the initial defender remains in front of Plum, which requires deft footwork and balance to stay poised and square to the ball handler. 

The second part of the clip shows Westbeld operating the same function, not just slowing Diggins down but tying her up with a Held steal at the end.

ICEing

I previously mentioned how ICEing, or using an aggressive double off a screen in conjunction with the baseline, can disrupt offensive flow. Below are a couple of fantastic examples of that.

In the first part of the clip, note how aggressively Westbeld attacks the rookie Sonia Citron off the screen. Such wing pick-and-roll attempts are also risky; smart positioning by defenders can ice ball handlers quickly. Westbeld immediately uses the baseline and Whitcomb to trap Citron and force a turnover.

The next part of the clip shows Brown blitzing Sabrina Ionescu, one of the best pick-and-roll operators in the WNBA. Done repeatedly will lose its effectiveness, but Brown here immediately leaves her assignment to Jonquel Jones, trapping Ionescu along the baseline, and giving her no outlet. 

The Alyssa Thomas Effect

There’s no question that the improved defensive effectiveness this season is greatly due to how smart a player Thomas is in general, let alone on the defensive end.

Thomas is one of the most active defenders in the league, purely because she keeps her head on a swivel. She’s ferocious, baiting her defender and waiting for the perfect moment to strike. The clip above is a perfect example of what Thomas can do.

Watch her activity—she positions herself where she can survey the perimeter without abandoning her defensive assignment. Recognizing the mismatch with a weaker ball handler isolated on Westbeld, Thomas gradually shifts in that direction, all while keeping track of her assignment. Then, she times it perfectly and pounces for the steal.

Thomas is one of the league’s top defenders thanks to these qualities, and combined with the team’s attention to detail on that end of the floor, she’s helped make them one of the best defensive units this season.

In a league defined by offense, the Phoenix Mercury has built their identity on relentless, intelligent defense. With disciplined rotations, aggressive perimeter pressure, and unwavering intensity, they’ve turned stops into momentum and defense into a weapon. As the season progresses, their defensive prowess remains the foundation of their success—and a warning to every opponent they face.

Stats as of July 11. Unless otherwise noted, all stats courtesy of WNBA.com and Her Hoop Stats.