"Most importantly, I tell them to watch out for the screens," says Stephen Duncan, laughing. Duncan is a basketball lifer: after playing in both junior college and Division II, the Westchester native has stayed in the game by training teenagers, helping run a local AAU program, and even shagging rebounds during late-night practices for Mike Bibby and Iman Shumpert when they were with the New York Knicks.

Duncan knows people, which is perhaps his most valuable skill. At a moment's notice, he can assemble at least five guys for a pick-up run at any skill level. That human Bat Signal ability is why several years ago, when he was hanging with Bibby and Shumpert at the Knicks' Westchester practice facility, former New York Liberty assistant coach Monique Ambers asked Duncan for his help .

"She heard I was from the area, and she wondered if I knew any guys for the team to scrimmage against," says Duncan. He did, of course, and since 2011, Duncan has staffed the Liberty's all-male practice squad.

"I also tell the guys to pay attention to what's going on and the women's movements," he says. "But those screens... my guys quickly learn how physical the women are by the screens they set."

Using men to fill practice squads and compete against women's basketball teams isn't new. Since when, exactly, is hazy—the method caught on with Division I programs during the 1990s, though some college coaches began stacking the rosters with men way back in the 1970s—but the idea behind it was always the same. "It changed the whole complexion of our team," Geno Auriemma, the legendary coach for UConn's women's team, said in 2007. "The intensity level, the quickness, the strength you have to play against those guys I think prepared us to play at higher level."

Jonah Herscu is in his second year as the Chicago Sky's head video coordinator; among his duties is finding guys for scrimmage fodder. "A practice player doesn't necessarily have to be physically superior to the players," he said. "Yeah, you are there to beat them up, and be faster and stronger, and make all your shots. But your job is to make the players better, not just go isolation for a sweet play that would make SportsCenter."

Though men are used for both college and WNBA practices, the level of competition noticeably changes at the pro level. The game becomes quicker and more physical, which requires practice players a couple of steps above, say, the men's ultimate team that had doubled as the practice opponent at Herscu's Division III school.

Phillip Barrett, Kyle Dawicki, and Anthony Tepedino are seniors at the University of Arizona. After a few years of suiting up for the Wildcats' practice squad, the trio tried out for the Phoenix Mercury's scrimmage team. All three made the five-man squad, out of 100 applicants. "At Arizona, it's a little more drill based and stop and go, talk about what is right and wrong about a play," says Tepedino. "But if you are not bringing it against the Mercury, you will get beat down."

Practice makes perfect. — Photo by Brad Rempel-USA TODAY Sports

Most WNBA teams stock their teams with high school or college players, guys with fresh legs who have a few hours of free time in the middle of the day. Herscu has worked to build relationships with AAU programs and college teams throughout the Chicagoland area. In Westchester, Duncan takes note of which his pupils have high basketball IQs and can quickly pick up the varying rhythms of a scrimmage. Once August turns to September and the WNBA playoffs loom, though, all those high school and college players have to return to class. This leaves Herscu, Duncan, and other organizers with some holes in their rosters.

That's why the elite practice squads often feature guys chasing the pro dream overseas or in the D-League. "We have a few quality players this year, but we've lost some guys over the past two years who were really good," said Eric Thibault, who works for the Washington Mystics. "One guy kept trying out for the D-League, and we've seen less of him this year."

"It hasn't affected the quality of our play," he continued. "We've just kept the circle of guys tighter, and we will probably look to shake up the roster next season."

When they tell you that you have to scrimmage against the Lynx. — Photo by Robert Deutsch-USA TODAY Sports

The most famous alumni of a WNBA practice squad is arguably Tyus Jones, who led the Duke Blue Devils to a national championship as a freshman and was a first-round draft pick in 2015. Jones is now on the Minnesota Timberwolves, which is a homecoming of sorts: in high school, Jones played sparingly against the Minnesota Lynx.

The existence of these teams isn't a secret—the New York Times covered DI practice squads in 2004; other outlets have profiled the tryouts—yet Jones is largely an anomaly in the world of practice players. Usually, they are complete unknowns to the public. Sometimes their WNBA team will shine a light on them—the Seattle Storm, for example, sometimes acknowledges their practice competitors during home games—but this certainly isn't a path to basketball fame and glory.

So why do players sign up for anonymous beat-down duty? Ego, interwoven with confidence, is a foundation in sports, and these players have to deeply bury that part of the psyche when they step on the practice court.

Rasul Shabazz has been a practice player for the Sky for almost four years, and he is Elena Delle Donne's foil. "Elena had done an interview on ESPN's Highly Questionable and was asked whether an ordinary guy could come into the gym and score on her," he says. "Her answer, and I quote, was 'Well, we have practice players who have played college ball, and we give it to them."

He continues, "I took it personally—I am one of those college guys. But I can't be mad, because she is right."

These practice players also don't get paid, which makes them a rarity in professional sports—even career NFL scout players earn a paycheck. Instead, their compensation is a free meal here and there, along with the odd piece of leftover gear. "I am very upfront about that," says Herscu. "I try and do a good job of explaining that they won't get paid but they can get free tickets to the games."

A practice player is a seasonal employee, mostly, faceless and essentially disposable. Which is not to say they're anything but valuable: what they contribute daily in practice helps determine how well a team does that year. The goal is to push each player on the roster to her limit, yet it can be a fine line between that and overshadowing, overwhelming, or simply going too hard. "Sometimes the women are sick of seeing the same guys," said Thibault. "Someone might be a bit too reckless. But we want them to be physical and to annoy the players."

They've got next. You, in this scenario, are a guy who really likes playing basketball. — Photo by Mark J. Rebilas-USA TODAY Sports

There are practice players who refuse to be just blips. These guys return year after year, structuring their regular lives around the demands of a pro team that will never give them a paycheck. For them, the five-month season is their time to shine. There is at least one returnee on the practice squads of each of the 12 WNBA teams.

Duncan, for instance, has been stocking his Liberty practice troupe with the same four guys since he began. They're all from the White Plains area, and if Duncan hasn't trained them himself, he's confident that they can compete with the pros. "They are the guys I make sure I text first when I fill out my roster," he said. "With those guys, they already know what offenses to run against the Liberty defense."

Since the Liberty has the league's staunchest defense, with a vice-like ability to slow down even the WNBA's most electric scorers, the efforts of Duncan's regulars have been vital.

For any team, the practice regulars view themselves as more than just a rented pair of Nikes: they are trainers, responsible for ensuring that whomever they guard is fully prepped for what she'll face the next game. "The three of us understand what we do is integral to helping Phoenix defend their 2014 title," the Mercury's Tepedino said. "So we approach the practices with a bit more determination."

Shabazz has matched up against 6'5'' Delle Donne since she was drafted in 2013. Sky coach Pokey Chatman told Shabazz his job was to make Delle Donne better, and so he attacked her weaknesses, forcing her to use her right-hand and bothering her with his wingspan.

That approach worked during her first two WNBA seasons, but then Shabazz noticed a change. "She flipped the script on me," he said. "Instead of me studying her, she is watching me. I can write what she is going to do in practice on a sheet of paper, but she has too many counter moves now and I am left guessing."

That competition in practice has translated into results on the court: Delle Donne is nearly a lock for the league's MVP award this season, averaging more than 20 points per game. "I am by the visitors' bench during games," Shabazz says. "And the opponent talks about how to stop Elena. 'She's only going left!' I think, Well, you know this is all she's been doing, but you still can't stop it."

The mainstays feel some pride at devoting their summer months to this unorthodox gig. Plunk some random dudes down on the practice court, which happens on occasion to every WNBA team, and the model breaks down. "Sometimes we have to recruit a newcomer, and it hurts us bad," said Shabazz. "They don't know how to ICE, or show, on a screen. They are still in pick-up mode."

The WNBA practice regulars make up a unique club, and they hold onto their membership for as long as they physically can. The benefits outweigh the lack of compensation—where else can an unknown match up against All-Stars and future Olympians? "When we are on the court, you have to be focused and be there to play," said Dawicki, of the Mercury. "When you are not in the game, it's crazy to say we hoop with Brittney Griner."