The 2018 NBA Draft is loaded with potential second-round sleeper picks. But some sleepers are years in the making. These are the long-term Cinderella stories of the NBA Draft.

We're talking about seven distinct players who project as certain or possible first-round picks. What do they have in common? They were never considered eventual NBA material when they were evaluated and recruited as high-school-age prospects. For some players, one year of college changed everything. For others, it took a full four years to play themselves into the first-round conversation. 

These players are hoping to follow in the paths of Russell Westbrook, Stephen Curry, Jimmy Butler, Damian Lillard and Victor Oladipo. All of those NBA All-Stars were ranked three-star (or not at all) and well into the 100s or lower in the overall rankings as high schoolers.

So how does someone go from being ranked 326th in his high school class to a guaranteed NBA contract? Khyri Thomas, Creighton's first-round-caliber combo guard, has the answers. It is fascinating how a player perceived as so relatively ordinary at 17 years old can morph into one of the best two-way pro prospects in a two-year timeframe. I tapped 247Sports recruiting experts Evan Daniels and Brian Snow as well as some of the players' college coaches to help explain how these players grew into their games.

Donte DiVincenzo (ranked 124 in class of 2015

As a high schooler: "DiVincenzo was a known commodity in high school and he played on a fairly loaded AAU team in Team Final (from Pennsylvania), so he certainly wasn't lacking in exposure. At that time, DiVincenzo was impressive athletically, but he lacked consistency as a shooter and there were question marks regarding his position and if he could develop into a full time point guard, which is still a legitimate question to this day." — Daniels

What changed: Obviously the national championship game is the obvious answer. DiVincenzo, who had a medical redshirt in his first season after playing 10 games, was a good player for Jay Wright the past two seasons. But his 31 points off the bench in the title game against Michigan put him into this situation. Had DiVincenzo scored eight points nonchalantly, the belief is that he would have tested NBA waters but ultimately decided to return.

Still, one huge game didn't turn DiVincenzo into a potential top-20 pick. He had a wonderful combine showing, but even before that he was developing at Villanova with his shot and proving to be much more than an energy guy off the bench. He averaged 25.5 minutes in 2016-17, then bumped up to 29.3 last season. He shot 57.3 percent from 2 and 37.8 from 3. 

His trajectory accelerated thanks to a 3-point-oriented Villanova offense that utilized spacing, was sophisticated in its screen-and-release read schemes, and allowed DiVincenzo to contribute playing alongside Jalen Brunson, Mikal Bridges, Josh Hart, Kris Jenkins, Omari Spellman and Eric Paschall

Jacob Evans (ranked 130 in class of 2014)

As a high schooler: "Much like the reputation he built over the course of his college career at Cincinnati, Evans was known for his scoring ability in high school and was ranked between the 80s and 130s throughout his high school career. A native of Louisiana, Evans had a powerfully built frame early on and he was equipped to score it from all three levels. But the question with him was: Could he maintain that in college? Which clearly proved to be true. Evans was heavily recruited and Cincinnati beat out the locals to pull him to campus." — Daniels

What changed: Getting to Cincinnati was interesting and life-changing, as Evans didn't play on an elite AAU team and wasn't on one of the elite spring/summer circuits. "I don't even think he was on a circuit," Cincinnati assistant Darren Savino, who recruited Evans, said. "Evaluators could question how good is he? He was by far the best player on his team, but how good is the competition?"

Evans is a potential first rounder because of his scoring, but also because of his physicality and body improvement. Courtesy of Cincinnati, here's his transformation from when he first got to campus.  

Pound for pound, Jacob Evans is one of the most physical prospects in this draft.  Cincinnati Athletics

Evans is going to earn burn in the NBA because of a wanted combination: He's a muscular, sturdy 6-6 wing who likes to play defense and checks all the boxes, on and off the court. He's had no off-court issues, is smart and takes care of himself.

He's also proof that you don't need to be excessively impressive in one statistical category at a non-traditional power in order to be taken in the first round. Evans never averaged more than 13.5 points, 4.7 rebounds or 3.1 assists. Many times, teammate Gary Clark looked like the better player. But Evans has a game that has evolved into one that scouts and general managers expect to translate well to the NBA. 

Melvin Frazier (ranked 182 class of 2015)

As a high schooler: "Melvin played in the Nike EYBL for much of his prep career, so he was a player that was visible throughout high school. Among the areas that stood out with Frazier was his impressive athletic ability and massive wingspan. Where there were questions was with his position. His ball skills needed work and in high school he was much more of an undersized, energy power forward than a perimeter prospect, which held us off on ranking him highly." — Daniels

What changed: Going to Tulane allowed Frazier to maximize his skill set at the AAC level. Frazier's probably a top-10 athlete in this year's draft crop (and reminded evaluators of that with his performance at the combine in May). But athleticism almost never wins out alone. Frazier was a year-by-year developmental project at Tulane; he played less than 50 percent of the team's minutes as a freshman. 

Last season, as a junior, the 6-6 wing logged 82.6 percent of Tulane's minutes and was able to improve his all-around game. He remained a top-level defender in the conference while boosting his 3-point shooting from 26 to 39 percent He went from 55 to 62 percent from 2-point range, and took 70 more shots from 2016-17 to 2017-18. It can't be overlooked that Frazier was coached by Mike Dunleavy, who has decades of NBA experience. 

Zhaire Smith (ranked 194 in class of 2017)

As a high schooler: "This is one of the more interesting cases, as I personally only had one logged viewing of Smith, and it came during May of 2016. In my evaluation notes, I had him listed as a 6-foot-5 versatile forward. Here were my raw notes: 'Good athleticism; quick off his feet; good instincts; struggles handling the ball; made plays in transition; somewhat in between positions; did connect from mid-range on a pull-up; complete non-threat as a shooter from 3.' Obviously, Smith made rapid improvements, but the lack of evaluations made this a difficult player to project." — Daniels

What changed: Smith is the only one-and-done college player on this list, which makes sense. It's rare for a one-and-done talent to be ranked below 30th, let alone hovering near the 200 line in high school. Smith wound up slipping so far because he was a "side gym guy," according to Chris Ogden, who recruited him to Texas Tech and won out over Texas, Oregon, Kansas State and Georgia Tech

"First thing I saw with him was freak athleticism," Ogden said. "When I see freak athleticism, I always try to say, 'OK, what other boxes does he check? Why isn't this guy a high-major player?' You go through it and watching him in high school. He did make catch-and-shoot shots, and was a good passer, and the only thing he didn't have was the ball handling." 

Smith is potentially going to go in the top 15 because of his wildly fun athleticism; his pop off the floor and his second jump are elite. He has fantastic instincts on defense because he came up playing in a system with a lot of press, so he has an anticipation to his defense that accentuates his fitness. 

Smith slipped so low in the rankings because he didn't have a scoring mentality, and still doesn't. He won't be asked or expected to score 15 or more per game. Yet he had a 125.1 offensive rating, which is outstanding. He shot 57.4 percent from 2. "He is an unselfish guy," Ogden said. "If you watched him in AAU but didn't watch him in high school, you saw a different player." 

Smith is similar to DiVincenzo in that NCAA Tournament performance and winning helped his case. Texas Tech made its first Elite Eight in school history last season. Because of that, and his motor, Ogden said he parlayed an opportunity a year ahead of schedule, if not two. "Any time you have a freak athlete like that that wants to work hard, he's going to give himself a chance," he said.

Jevon Carter (ranked 299 class of 2014)

As a high schooler: "Jevon Carter was always a known commodity coming out of Chicago. Despite playing at a legendary high school, he was never a dominant player either in high school or on the AAU circuit. West Virginia was the only high major to really recruit him, and people questioned if he shot well enough to make an impact in college." — Snow

What changed: West Virginia's varied pressing scheme boosted Carter's stock. It took him four years, but he proved to be a winning player who commanded respect from teammates and opponents alike. 

He's the only senior on this list. It's been quite a trek for Carter to get to this point. If he doesn't go in the first round, he'll be a good bet to get snagged in the 30s. Few players in this draft have better all-around man-to-man defensive strengths than the 6-2 Carter. The fact he's undersized only makes his push to NBA Draft all the more impressive.

There isn't a lot of secret science to how he got here. Carter was a dream for Bob Huggins when he found him. The coach chiseled away and built an all-time player at West Virginia over the course of four years. Carter finished off his career by averaging 17.3 points, 6.6 assists, 4.6 rebounds and 3.0 steals. He shot 39.3 percent from 3-point land. 

Every year he got better. 

Jerome Robinson (ranked 308 class of 2015)

As a high schooler: Daniels and Snow never scouted Robinson on the circuit. In fact, he was someone you had to go out of your way to see.  Robinson played for an AAU team run by the brother of Golden State Warriors forward David West. In high school competition, he played on the same team as former Kansas star Devonte' Graham, who's also hoping to be drafted this year. 

"They were off the beaten path," Boston College coach Jim Christian said. "He was so skinny, but his feel for the game was evident right from the beginning. The only school recruiting him hard at the start along with us was Richmond. He was our kind of kid." 

What changed: Boston College is still in the midst of a slow turnaround. But last season, when Robinson was a junior, the Eagles broke through to win 19 games, the most in Christian's tenure. Robinson was the key player in his first recruiting class.

Robinson's father was an overseas pro. His mother played volleyball at South Florida. They bought in on their son taking a tougher route and trying to get Boston College out of the ACC's basement. "To rebuild the program, not one time did I ever have to go back to North Carolina to re-recruit him," Christian said. "Think about that in this day and age. He saw the vision, saw what was going on. As a freshman he had some really big games and then he broke his wrist and missed half the ACC season. He kept getting better, developing, and a lot of it is confidence. He became consistent last season, and he had one bad game in 21 games." 

Consistency and a boost in confidence are why Robinson is almost certainly going to be a first-round choice. It's a massive jump from last year, and when looking back to his high school days, it's remarkable to see how high he's moved. Robinson became obsessed with being a dependable performer. Not just having one good game and then failing in the next. His 2-point shot went from 45 percent to 53 percent. His foul shooting jumped from 65 percent as a freshman to 83 percent as a junior. And on top of all this, he's a lengthy wing who hit 41 percent of his 3s. 

Robinson figured to have a good shot at being picked a couple months back, but in early April he was far from widely viewed as first-round material. And now, no player seems to be a faster riser in the draft over the past month than him. Christian thinks he's going to be picked in the teens. 

Khyri Thomas (ranked 326 class of 2015)

As a high schooler: No potential 2018 first-rounder was more lowly rated. Daniels and Snow did not log evals on him, which is just a reality of attempting to see and scout so many prospects at so many events. It makes Thomas' story all the better. Thomas didn't play in big spring and summer non-scholastic events. He was with Omaha Sports Academy and attended Benson High School in Nebraska.

"Maybe he played in Vegas at a back gym," Creighton coach Greg McDermott said. "We were always intrigued by him, he was just up the street in north Omaha, and got to see a lot of him. His length and anticipation skills were always there. He took a lot of chances and gambled a lot. Shot was a work in progress but wasn't broke. Was a good kid, good teammate." 

Creighton was the leader from the onset. Amazingly, Thomas was uncertain of his worthiness to wear a Bluejay uniform. 

"Khyri asked us on several occasions, he would look right at us and say, 'Are you sure I'm good enough to play at Creighton?'" McDermott said. "He was so outside of the box in terms of the way most kids are. They feel like they invented the game, where Khryi had a lot of doubts and lot of confidence issues his freshman season." 

What changed: Thomas, whose build has been NBA-ready for a year-plus, put on 15 pounds of "the right kind of weight and muscle," McDermott said. 

He got stronger, and with that an ability to score through contact came. It clicked early into his sophomore year. "As Justin (Patton, the No. 16 pick last year) started to develop, scouts were at practices, games, shoot-around, and Khryi stands out because what you see in the game and how hard he competes shows in every drill," McDermott said. "His intensity and the fact he was a great teammate got him attention."

Thomas, like Robinson, vaulted his free-throw shooting. He went from 52 to 79 percent in two years. From Year One to year Three, his confidence meter was on a different gauge.  Then he was tasked with guarding the best scorers in the Big East every night. He did it to successful ends for the most point, and along the way blossomed into a 41 percent 3-point shooter and a 53.3 percent scorer from 2. He's an ideal modern NBA wing because of his athleticism, sturdy frame, defensive prowess and improved shooting form. He's also the biggest climber from his high school days. 

All these players' stories comprise what makes draft night so fun, so special. Some might not wind up going in the first round, but all of them will absolutely be picked. The dream will be achieved. Question is, who among this group can repeat the process and work themselves to an All-Star level?