Mohamed Bamba showed off his penchant for shot-blocking while at Texas and looks to take his defense to new heights in the NBA. (1:04)

MO BAMBA SITS on the sideline inside the gym at St. Bernard High School in Playa del Rey, California, and stares intently into his phone, which is on selfie mode. He cradles the device between his thighs, watching himself in his digital mirror, as he inserts into his right eye a contact lens. It looks like a tiny droplet on the tip of his enormous right index finger.

On Thursday, Bamba and a class of other top prospects will revel in the pageantry of the NBA draft in Brooklyn, but on the Friday entering Memorial Day weekend, he's a 20-year-old inside a nondescript school gymnasium with an old-school scoreboard and basic amenities, using an iPhone so he can see clearly.

Bamba, who is 7 feet tall, clocked into the NBA combine last month with a 7-foot-10 wingspan -- a combine record -- and a standing reach of more than 9 feet, 7 inches, tops among this June's draft class. He ran a sprint three-quarters the length of the floor in 3.04 seconds, beating times posted by Russell Westbrook and John Wall at previous combines. Out on the floor at St. Bernard, Bamba is the NBA scout's platonic ideal of a big man -- small boulders for shoulders resting atop a taut torso that narrows to a tiny waist, a perfect funnel of a body.

Bamba, contact lens in and iPhone stashed away, joins Drew Hanlen, his primary skills coach, for today's big-man syllabus. As Bamba unleashes a set of "dream shakes," finishing with a hook over his right shoulder, Hanlen implores him, "Don't miss short!" Dream shakes give way to attacks from the midpost, requiring precise footwork and explosion. These are the basic food groups that have defined the big-man diet for decades. Ten minutes in, Bamba glistens with a coat of moisture -- a one-on-zero workout at full speed is no picnic.

Before long, Bamba moves away from the paint. He ventures out to the far left corner behind the 3-point line, where he's fed passes in rapid-fire succession, three basketballs cycling through rotation among Hanlen and his staff. The book on Bamba, based on his one season at Texas, classifies him as an elite rim protector with Defensive Player of the Year potential. Although these glowing defensive reviews have been tempered by some who also regard him as a "raw" offensive player with limited range, he proceeds to drain 12 out of 20 catch-and-shoot 3-pointers. Moments later, he goes 16-for-20 from the right corner.

The remainder of this afternoon workout -- he'll return after supper for a night session -- mostly resides along the perimeter. Bamba will dance with Hanlen in a sequence of pick-and-pops. The big man will crane his lanky right arm into a right angle for a series of face-up jumpers off a variety of actions. Though Bamba towers over the court and everyone on it who's catering to his rapid development, if you squint hard enough, he appears nothing like the project centers of years past whose frame and stature he shares.

This 20-year-old giant on the floor looks like an aspiring NBA guard -- which is exactly what Bamba must become if he hopes to meet expectations when he's chosen in the front end of the lottery Thursday night. And after that, if he hopes to stay on the floor in the NBA.

In order to stay on the floor in the NBA, Mo Bamba knows he'll need to be able to space the floor. John Weast/Getty Images

WILT CHAMBERLAIN FAMOUSLY said, "Everybody roots for David -- nobody roots for Goliath." But for most of the National Basketball Association's existence, young Goliath prospects have had it pretty good, whether or not anyone was pulling for them. As noted by David Epstein in "The Sports Gene," a 7-footer in the United States has approximately a 1-in-6 chance of being an NBA player.

By virtue of their height alone, rangy big guys with expansive wingspans have always tantalized talent scouts, and for good reason. The objective of basketball has always been to insert a leather orb through an iron ring placed 10 feet from the floor. For decades, the reward for draining a shot from long distance was no greater than doing so from close range. Why bother heaving a shot off-balance over an aggressive defender from 15 or 20 feet away, when you can just flick the ball -- which most big men can control with a simple grip of the hand -- from your perch overlooking the court?

The biggest men on the floor, historically, have controlled the game defensively. And as typically the highest-percentage proposition on the menu of options, they could also dictate its terms offensively. Bill Russell was the cornerstone of basketball's greatest dynasty, and an elite big man was compulsory for any team with championship aspirations.

If a big man offered even the faintest glint he could grow into one of those pivotal titans, a team would come calling in the lottery. No discernable offensive skill set? Then we'll just call him a project because you can't teach the combination of height and hops. And if, lo and behold, he's Stromile Swift, his wait in the greenroom will not last long.

As recently as the 2010-11 season, some intelligent basketball minds preoccupied themselves with the notion that the Miami Heat's chances of winning a championship would be enhanced considerably if they could only sign Erick Dampier, because Chris Bosh -- and Zydrunas Ilgauskas and Joel Anthony and Jamaal Magloire -- weren't enough when Udonis Haslem became injured.

But over the past few years, the game has transformed itself into one in which pace, 3-point shooting and playmaking dominate. The most forward-looking teams have decongested their offenses, taking centers from their workspace down on the block and, in many cases, relegating them to the bench. Those who stayed on the floor are now required to switch out on the world's most lethal point guards and tread water. On offense, they must find a way to be useful away from the basket. And in many cases, if a big man has any hope of getting more than a handful of shots at the rim, it's because he darted to the top of the floor to set a screen, then dove at full speed. The post-up? It's the landline of basketball.

The best team in a generation has rarely employed the services of a big man in the most crucial moments of its dynasty, and teams that in the recent past carried five conventional big men now have room for only one -- anyone else had better have a 15-footer, at minimum. Unless a big has Rudy Gobert's profile, those with limited range need not apply.

This is the disrupted world Mo Bamba enters, a forbidding landscape with nowhere to hide -- one that demands learning new tools to survive.

IN THE EARLY spring, soon after he arrives in Los Angeles to begin his immersive pre-draft training, Bamba sits inside a conference room at Hanlen's condominium complex, not far from St. Bernard. The task today is to identify impact NBA big men and the qualities Bamba admires about them. Among the names and features scrawled on the whiteboard in dry-erase ink are Nikola Jokic (footwork, shot fake), Anthony Davis (handle, ability to create), Karl-Anthony Towns (shooting, hook shot) and Draymond Green (decision-making, passing).

Bamba is prompted to identify some assets of his -- physical play, post work, screening, swag -- and boil the list down to three primary items that would be the focal points of the next two months. His finalists, in descending order: shooting, mid-post and low-post work, and mobility.

A few months later, in late May, when Bamba is asked about his aspirations, he speaks in general and ambitious terms common among highly touted prospects -- being a top-flight professional at his position, winning championships, induction at Springfield. But he's also quite specific about the most immediate goal, one that's proved to be an increasing challenge to even the most capable centers in the NBA.

"I want to put myself in the best position to stay out on the floor," Bamba says. "There's a reason why a lot of bigs aren't on the floor [at the end of games]. They can't guard those smalls. They can't shoot."

The prior night, Bamba had watched Game 5 of the Western Conference finals between Golden State and Houston. The game is a defensive struggle, and Bamba had noted Clint Capela, a big man whom he admires and shares commonalities with physically, didn't play in the pivotal final six minutes despite scoring 12 points (5-for-6 shooting), gobbling up 14 rebounds and rejecting two shots.

Bamba says he appreciates the Warriors' small-ball game, how it's influenced basketball and, most important, the demands it places on anyone -- particularly big men -- who want to be a member of any future "lineup of death."

"When Golden State goes small, having those skills can separate me and allow me to stay on the floor," Bamba says, firing up a video file titled "Mo Switchability and PNR Defense." "That's why shooting is at the top of that list, because spacing the floor is so important. It's how you stay on the floor."

play 1:22 Mo Bamba drains 3s ahead of NBA draft Bomani Jones and Pablo Torre weigh in on where Mo Bamba could land in the NBA draft after seeing the former Texas forward's recent workout.

BAMBA'S SHORT-TERM rental apartment in Marina del Rey is decidedly adult in accoutrements and mood. A large, 4-foot-tall chalkboard drawing of the New York City subway system -- Bamba is from Harlem -- hangs on the wall. A chess board sits on the coffee table, the ongoing game with an associate paused for a bit. Shoeboxes are stacked neatly in a three-box-by-seven-box wall to the left of the television.

From the couch, Bamba watches himself on the living-room TV launch jumpers from the perimeter, another in the series of video clips anywhere in length between 20 seconds to three minutes assembled for him by Hanlen's lead videographer. He's immediately drawn to his mechanics, specifically the alignment of the right side of his body as he moves into his stroke.

"Think of it as a line that connects three dots," he says while tracing that line with his left index finger. "Your hip, to your armpit, to your elbow. Ideally, this should be a 90-degree angle. I have long arms, so it's hard."

Bamba motions back to the screen and a paused image of him releasing a top-of-the-arc jumper in his burnt-orange Longhorns jersey in a game at TCU. A large graphic appears at the bottom of the screen -- a timer that starts from 0.00 -- as he catches the ball. The video resumes and the clock times Bamba's shot, which falls through the net, at 0.93 seconds.

"There's a reason why a lot of bigs aren't on the floor. They can't guard those smalls. They can't shoot." Mo Bamba

"You see how far back it is?" Bamba asks, examining the angle of his upper arm. "I was shooting at 122 degrees. It's way up here. It might go in, but it takes longer and doesn't go in as softly."

The Texas clip flows into footage from a more recent workout at St. Bernard, where Bamba stands at the identical spot at the top of the floor, fed by one of Hanlen's guys. This time, Bamba clocks in at 0.75 seconds.

"Look where I'm releasing," Bamba says. "Now it's about 105 degrees -- not 90, but it's a lot better. Those degrees speaks volumes."

It's not as if big men from past years didn't work on their mechanics. Plenty of lore exists of Shaquille O'Neal, Dwight Howard and DeAndre Jordan practicing free throws ad nauseam. But the proportion of time devoted by Bamba and his coaching and training staff to the science of shooting represents a profound departure from even 10 years ago.

Clip after clip: Bamba shooting 20 shots from the right corner; Bamba playing pick-and-pop with Hanlen from well beyond the arc on the left side, then the right side; Bamba brandishing a jab step that might prompt Carmelo Anthony to nod in approval, then skipping baseline for a jumper; Bamba creating separation to step back for turnaround 17-footers.

Yes, there are some classics of the low-post genre and a few rip-and-drives on the clips of his greatest, but Bamba's level of absorption isn't so intense as when he's charting his improvement from distance. Those are old standards -- Bamba knows them, can trot them out when asked to. But those low-post moves are essentially off-menu items in today's NBA: available if ordered, but rarely requested.

Bamba is entering a league where the game has changed dramatically for big men. Scott Winters/Icon Sportswire

BAMBA IS SWITCHING gears with the hum of a German transmission. We're still watching the "Mo Switchability and PNR Defense" clip, and the Longhorns are battling 16th-ranked TCU. The Horned Frogs move instantly into a high pick-and-roll. Texas' typical coverage calls for the big man guarding the screener to corral the ball handler once he bursts off the pick.

Over the past few years, the NBA has experienced a defensive revolution that, not unlike the shifts in offensive strategy, requires big men to hold their own while covering speedy guards with nasty crossovers and outrageous speed. Bamba might be the best rim protector in the draft class, but these days interior defense composes only one portion of a big man's overall grade as a defender.

But on this play, Longhorns guard Matt Coleman gets taken out of the play by the screener, leaving Bamba with the responsibility to pick up the guard, Alex Robinson. It's a non-starter for Robinson, who knows better and kicks the ball out to the perimeter. Now TCU tries the second side -- another pick-and-roll snuffed out by Bamba on the switch.

"A lot of things we do in [physical therapy] address mobility, because opening up the hips will allow me to guard those smalls." Mo Bamba

So back it goes to the first side, into the hands of Jaylen Fisher out on the perimeter. Fisher feeds Ahmed Hamdy-Mohamed, who's situated deep in the lane. But Bamba, now guarding his third man of the possession, swoops in from the perimeter, where he's still on Williams, and swats Mohamed's point-blank shot away with his left hand.

The next clip shows Bamba on an island against Robinson, who waves off a screen. He wittingly wants Bamba one-on-one with the shot clock winding down.

"Whenever I guard a guard, I don't want to reach too much, but I will poke at the ball once to get him thinking," Bamba says, watching himself and Robinson face off like a couple of samurai, waiting for the other to make the first move.

Much of Bamba's comfort defending on the perimeter resides in good instincts, but the secret ingredient for any big man who excels defending a mismatch is biomechanical. "I knew he preferred not to shoot the ball, but dribble. He attacks as soon as I bring my left leg forward. But I backed off. As an offensive player, you want to attack the foot that's up so you can get the defender to turn his hips. But I don't think he knew I could cover ground that quickly. He tried to finish with his left hand, but I met him quick."

Bamba rejects Robinson's layup attempt, which caroms off the glass and into the hands of a Longhorns teammate, who ignites the break. A triumph of length, but also of a less-tangible skill Bamba is spending a ton of time honing.

An elite rim protector, Bamba can use his enormous wingspan against guards on the perimeter, too. Chris Covatta/Getty Images

"IT'S ABOUT HOW you turn things on and off in an instant," says Rory Cordial, who is Bamba's physical therapist and performance coach. "If you're facing Step Curry in that situation, you can't be tight or tense. You need to be loose and free so you can respond to the situation. He's working on the ability to drop down and play from a lower position."

Just as Bamba might attempt 100 3-pointers in a given day to build the confidence to shoot from the perimeter, he'll perform all kinds of exercises in an effort to gain the same level of poise when the Warriors, Rockets, Thunder and Trail Blazers draw him in a switch against the most dangerous point guards alive. In his sessions with Cordial, Bamba spends a fair amount of time in the plank position, what yogis call "the top of a pushup" and what Bamba says is "good for you ... in a take-your-medicine type of way."

Cordial will have Bamba hold himself in a plank position, then lower and immediately pop back up -- not so much a pushup, but an explosive burst while maintaining the integrity of his position. It's the "off and on" capacity Cordial mentioned.

"When you talk about moving like the little guys, it's starting to use that strength and power he's developing, where he can impulse his force," Cordial says. "He can be rigid and strong to resist in the post, but then let go in an instant and spin off, let his body move."

Then there are the hips, which unlock it all for a big man -- the mobility, the switchability, and any number of tasks associated with the kind of versatility the game now necessitates. The burning questions for Bamba are how much motion does he have in his hips, how deep can he squat, what kind of flexibility and stretch does he have? Most important might be: How can a big man control that range of motion?

Among the stunts Bamba is subjected to: bungee training. A belt will be wrapped around Bamba's waist, with a trainer holding the cord, which looks like a long leash. Bamba will resist the movement, or be pulled into it as if he's facing off against Curry and his ungodly crossover. Suddenly, Bamba will feel a quick tug, forcing him to work against that additional resistance.

When you watch Al Horford, one of the best perimeter-defending big men ever, or 6-foot-11 Giannis Antetokounmpo face off against an opposing point guard, you're watching guys who are engaged in a very specific exercise: the complete control of their movements faster than a Westbrook can explode, faster than a Curry can cross over. Nobody ever suggests that Horford or Antetokounmpo take a seat when the outcome of a game is in the balance. But it isn't their length or their shot-blocking potential or interior D. It's the hips and the unshakable confidence that those hips will follow orders.

"You want to work ahead of it," Bamba says. "That's why a lot of things we do in [physical therapy] address mobility, because opening up the hips will allow me to guard those smalls. Without the mobility, you don't stay on the floor. And I want to be on the floor."

play 0:59 Bamba heads home to New York for the draft Mohamed Bamba packs and flies from Atlanta to New York, as he returns home for the NBA draft.

IN THE 2004-05 NBA season, 32 players who were classified as centers played more than 1,000 minutes. This past season, that number was down to 23. The success of the Warriors, the rise of the 3-point shot and, more recently, the prevalence of switching defenses have rendered less-skilled and less-mobile big men a liability.

This hasn't deterred the scouting department of NBA teams from being wowed by Bamba's class of incoming bigs. Front offices clearly aren't subscribing to the belief that such players are expendable. Five of the first six prospects projected to be selected in ESPN's mock draft are classified as centers or center/forwards.

A primary reason? The prospects have witnessed their slightly older counterparts in the league waving towels from the sidelines in the fourth quarter. They see that those who aren't are Joel Embiid and Horford -- multifaceted bigs with a guard's tools. They've been told by agents and workout gurus that millions upon millions of dollars rest on their capacity to space the floor for coaches who are trying to build an offense that can compete with Golden State and Houston.

Accordingly, Mo Bamba will continue to chart the angle of the crook of his elbow, and time the duration of his release. He'll be yanked by bungee cords and held in plank positions for what seems like days. He'll treat his hip flexors like a prodigy pianist cares for his fingers, because the nastiest crossover dribbles, the likes of which he's never seen, await him in October.

And more than anything, he'll push back on the idea that he's the last of an endangered species.

"I don't believe in the big-man crisis and big-man problem," Bamba says. He's finished his Chipotle and is eager to get back to the chess board, where he's gained a significant advantage over his opponent by virtue of his last move, before heading back to Hanlen's gym for what promises to be a grueling night session. "The game I play and the game I'm working toward, that problem really doesn't exist for me."