At the top level of men’s college basketball, where teams harbor national championship hopes and NBA talent, most of the competitors are African-American. But one group of players remains predominantly white:

The walk-ons — players who don’t receive athletic scholarships, pay their own tuition, room and board and do the dirty work in practice, all in exchange for a small role in big-time basketball.

This is not a story promoting the false idea of the “white scrub” or the mythical superiority of the black athlete. But the optics beg the question: When we look at the end of the benches during this year’s NCAA tournament, why will most of the faces there be white?

After discussing the issue with players, coaches and observers, I believe some of the same economic, social and cultural forces that make basketball a predominantly black sport affect the walk-on population, but in reverse. These factors — a lack of wealth in the black community, fewer connections to powerful institutions, and basketball’s grip on the culture and psyche of so many young black men — push many African-Americans away from a valuable opportunity.

In an American value system that glorifies and overemphasizes sports achievement, there’s a stigma to being a walk-on. But the experience has many benefits, which are attainable for most high school players without Division I hops, handle or height.

“White boys come here and don’t mind walking on. They know how to leverage the walk-on experience into lucrative coaching or corporate careers. That’s something the brothers don’t do,” said Leonard Moore. He’s founder of the Black Student-Athlete Summit and a professor and associate vice president at the University of Texas, whose basketball team lists two walk-ons, both white.

“These white players know they’re never going to play, but they don’t care,” Moore said, “and they leverage that experience for the next 40 years of their life.”

My review of rosters of the Top 25 teams from Monday’s final regular-season AP rankings showed at least 59 current or former walk-ons. Forty-nine are white; nine players are black; one is Chinese-American.

“White boys … know how to leverage the walk-on experience into lucrative coaching or corporate careers. That’s something the brothers don’t do.”

In contrast, Division I men’s basketball in general (excluding historically black colleges and universities) was 27 percent white and 53 percent black in the 2016-17 season, the most recent year for which NCAA statistics are available. A review of this year’s NCAA tournament rosters shows about three-quarters of the walk-ons are white.

“The numbers really did surprise me,” said a veteran assistant coach in the ACC, who spoke on condition of anonymity. “It’s one of those things that’s so obvious, you never see. That’s the shame of it. I guess you become immune to it.”

Division I teams each have 13 scholarships but still need walk-ons to fill various roles: memorize the opponents’ plays, push the main guys in practice, populate drills and scrimmages when scholarship players are injured, rebound for guys who shoot the ball in games, and help bolster the team’s overall GPA and graduation rates. Above all, walk-ons must bring a team-first, hardworking, positive energy to every practice, game, film session and road trip.

At the top level of college hoops, walk-ons usually fit into one of several profiles. A few have the talent to play at a lower level but wanted to give the big time a shot. They arrive on campus hoping to become the next Ron Baker, Jeff Hornacek or Scottie Pippen — walk-ons who earned playing time, and a scholarship, and made it to the NBA.

Many others are undersized but have a connection to the school through parents or extended family. Lots of them are local kids who grew up idolizing the program. Others are willing to do anything to fulfill their dreams of being a Division I player. I found two walk-ons with an older brother who also walked on, one son of a walk-on, and two walk-on brothers playing at UCLA this season.

If you peruse enough college rosters, as I did, the walk-ons start to jump out from the team photos: white Americans of average height in a sea of large, mostly black or European young men.

Here’s how that happens:

RUN THE NUMBERS

In 2016, the median net worth of white families was 10 times larger than for black families: $171,000 for whites and $17,600 for blacks. The average four-year cost of a college degree ranges from about $57,000 for in-state public college to $104,000 for private. For a black ballplayer with a Division II or junior college scholarship offer, it’s much less likely his family will pay out of pocket so he can ride the bench in Division I.

“It’s money. It’s financial. It dictates a lot of things,” said Jamion Christian, head coach at Mount St. Mary’s University in Maryland. “How many students have to work jobs, but walk-ons can’t work a job because you have to commit to the team.

“I wish more black kids would take that walk-on opportunity. It would help bring more young coaches into our profession,” Christian said. “I’m looking at the bench for coaches. A lot of these white assistant coaches get in at that level and work their way up. I’m looking at hiring young black guys, and they’re hard to find because financially they may not be able to do it.”

In the 2016-17 season, 75 percent of Division I coaches were white; 22 percent were black. “When looking for walk-ons, either those you recruit as ‘preferred walk-ons’ or those who just come by and try out, coaches tend to want certain characteristics,” said one white assistant coach at a mid-major program who spoke on condition of anonymity. “Being a walk-on is a thankless job at times, and coaches may have a tendency to subconsciously choose individuals that are like themselves.”

Another equation working against black walk-ons is the percentage of black students at the big-time colleges. Many walk-ons come from open-call student tryouts. At Villanova, for example, black men are about 3 percent of the student body. All four of the Wildcats’ walk-ons are white. (One is the son of the Philadelphia 76ers’ team president.)

Also, “a lot of walk-ons at high-major schools have a connection to a big-time booster, maybe a relative or something of that nature,” the mid-major assistant said. “Head coaches will take care of a kid knowing the booster has their back.”

“I wish more black kids would take that walk-on opportunity. It would help bring more young coaches into our profession.”

After a decorated high school career in Birmingham, Alabama, that included two state championships, 6-foot guard Patrick Keim had scholarship offers from mid- to low-major Division I schools such as Georgia State and South Alabama. But his father, who owns a medical supply company, and his mother, a registered nurse, both attended Auburn, as did his two brothers. In 2014, Keim enrolled in Auburn’s engineering school and was preparing for life without basketball when he heard the new head coach, Bruce Pearl, wanted to talk to him.

“I think some donors told Coach about me, he saw my tape and wanted me to be a preferred walk-on,” Keim said.

Keim got meaningful playing time his sophomore year because of injuries to other players. Auburn finished 15-20. He then returned to his role as a leader of the scout team, learning to run the offense of every Auburn opponent. His mission is to serve his squad, which spent this season in the Top 25 and is seeded fourth in the tournament’s Midwest Region.

A student ministries pastor, Keim offers spiritual counseling to his teammates and leads them in prayer. He evaluates potential walk-ons during open tryouts; Keim estimates 45 of the 50 players at the most recent session were white. And before each game, Keim plays one-on-one with Malik Dunbar, a 6-foot-6, 230-pound junior wing.

“I go as hard as I can. My goal is to do whatever I can to give him the most live experience before the game happens,” said Keim, who’s listed at 186 pounds. “I treat it like my national championship. I’m fouling like it’s a finals game. But when Malik gets in the game, the other team doesn’t go nearly as hard as I do.

“Every time I lock him up, he plays so much better in the game,” Keim said. “I’m not saying I’m a better defender. I just know the value of preparation.”

In December, Keim was awarded a scholarship for the final months of his college career, a common reward for dedicated walk-ons. He played 19 minutes over 12 games this season, scoring four points. The Tigers made the NCAA tournament for the first time since 2003.

“Especially my last year here, it’s been a dream,” Keim said. “Seeing this team build an identity, seeing this team understand who they are, once we figured out each other’s personalities, we’ve clicked really well. Honestly, the best part is just waking up and wanting to go to practice, wanting to spend time with these guys.”

FOR THE CULTURE

If ball is life, as the saying goes, then hoop courses through the veins of the black community. Our cultural identification with the game, our belief in its ability to uplift and transcend, has invested basketball with an influence almost rivaling the church (God, please forgive me) in many African-American homes.

With so much black identity and manhood tied up in the game, it goes against the cultural grain for players to seek out a low-status position. In other words:

Brothers ain’t trying to be nobody’s practice player. We talking ’bout practice. Not the game, not the game that we go out there and die for. Only play in practice? C’mon. We finna hoop.

“Our identity a lot of times is driven by basketball,” said Christian, the Mount St. Mary’s coach. “Something we try to do here is teach our players, basketball is what you do. It’s not who you are. The ability to grow our perspective on our own selves and what we can achieve becomes really important.”

“Our whole athletic socialization is different,” said Moore, the University of Texas professor. “It’s more central to our sense of self-worth. That comes from our family, teachers, pastors at the church: ‘You’re a basketball player.’ And so for me at 18 or 21 to say I’m going into coaching, what I’m saying is my basketball career is over. And it ain’t supposed to be over.

“These white kids have more self-awareness about their athletic ability than these black kids.”

Tommy Luce knew as a high school junior in Jeffersonville, Indiana, that he would never play Division I. He came off the bench that season, even though his dad was the coach. But his dad was childhood friends with Purdue head coach Matt Painter, and after Luce graduated, he became a Boilermaker. Now he’s a sophomore cult hero who led SportsCenter when he scored two garbage-time buckets against Lipscomb University.

“Just being able to be on the team is a really cool opportunity,” said Luce, who’s listed at 5 feet, 10 inches and 150 pounds. “I’ve just met so many people, have made a lot of long-lasting relationships. I can get a really good job when I’m done with college. I’ve met so many people, and coaches will help me get a job. Getting a degree from Purdue is a big deal.”

So is a degree from the University of Virginia, which U.S. News & World Report ranks third academically among public colleges. Its basketball team is currently ranked No. 1. Trevon Gross Jr. is the rare black walk-on, a 6-foot-3 point guard for Virginia’s “Green Machine” scout team, named for the color of its practice jerseys.

When he finished playing at prep powerhouse St. Benedict’s in New Jersey, Gross was getting looks from Division II and III schools. But his father graduated from the University of Virginia, and Trevon loved everything about the school, starting with the academics. He enrolled in 2015, spent a season as team manager, then made it through the open tryout and became a walk-on for the 2016-17 season. He played 27 minutes over 10 games this season, scoring a total of four points.

Asked why so few African-Americans walk on, Gross said, “I think it’s a matter of priorities for a lot of black men in society. A lot of guys just want to play.

“Walking on has this stereotype that it’s something embarrassing or looked down upon,” he said. “But that’s not the case. There’s still a lot of opportunity here for walk-ons, just like for scholarship players. You’re getting to know different programs within the school, meeting and working with different people, traveling all over the country. People know who you are, so it’s easier for you to talk to them. It’s very underrated.

“The hardest part is every day knowing that people will make fun of you for being a walk-on, and knowing that there’s a financial difference between you and the other players, having to deal with that from the outside world. It’s a daily battle. You have to be mentally tough to be a walk-on. It’s definitely far from easy.”

Now a junior, Gross is majoring in sociology and plans to stay at Virginia for a master’s in higher education. This season, when a scholarship opened up, it went to Gross, giving his parents an unexpected break from tuition payments.

Next season, though, Gross’ scholarship may well go to someone who will play during games.