Giannis has to be the answer here.

Pascal Siakam came into the league basically having picked up basketball like 3 years prior. He was starting in the NBA finals within 6 years of playing the sport.

Rudy Gobert was an unproductive backup center overseas. Most of why he got drafted was his freakish combination of height and wingspan

OG Anunoby really couldn’t shoot in college. He was putting up 56% from the line and 31% from three his final year at Indiana

Jalen Johnson was in the G league for a season and a half.

Kawhi Leonard

VanVleet. Undrafted to a max contract

Steven Adams. He was very raw skill-wise, but Presti knew he was smart enough to figure out how to be the savvy vet he is today.

From the scouting report of Nikola Jokic:)

Long-Term Projection As previously mentioned, unathletic players can survive in the NBA and even earn prominent roles.

If Jokic can deliver accurate shooting and make the right plays when the ball is in his hands, he could be a poor-man’s Diaw and a long-range threat like Antic. Jokic would probably be the fourth or fifth scoring option when he’s in the game, but all that matters is whether he plays efficiently.

Unfortunately, his defense will likely prevent him from ever playing 30-plus minutes or starting. However, there’s no shame in being a respectable reserve on a winning team in the future

I admit my bias but I’d say Naz Reid.

He was undrafted due to his weight (probably weighed more than Zion at his heaviest), got to a two-way, lost weight, did well at the g-league level, find a way onto the main roster and managed to snag 6th man of the year and could now start for a lot of teams.

Does Jerami Grant count? He’s not a superstar or anything but he had a very limited jump shot and a degree of carelessness with the ball in college that put him down to a second rounder despite his obvious athletic upside. Now he’s a productive nba player (though he never did quite figure out rebounding) who can score at multiple levels.

Danny Green. he was almost out of the league & when San Antonio took a chance on him he immediately became a great role player & was important to 3 different championship teams

Giannis, Embiid, Jokic, SGA

Giannis is the obvious one. Raw, skinny, not a finished product, turned into an all time force.

Pascal Siakam. Not a polished scorer early and was viewed as energy and defense, then built a real star game.

Rudy Gobert. Limited offensively, very raw, but the physical tools plus development turned into a generational rim protector.

Kawhi fits too. He was not some college scorer and his handle was rough, but the tools were there. He became an elite shot creator on top of being a monster defender.

If you want a deeper cut, Jimmy Butler. Not unproductive, but he was not a clear star at all, and he built everything year by year.

Jaylen Brown TBH - He was the no. 3 pick but he was quite a reach at the time and considered very risky. His shot was terrible in college and no one thought he’d be able to playmake for others. Also no one saw him reaching this level at the time of the draft.

Siakam. Late start to the game. Mid major. Raw as heck coming out. Hard to overstate how much polish he has added to his game. I have a lot of respect for him.

Giannis obviously also maybe Westbrook & Kawhi

Mark Eaton

Butler should be up there

Dort would probably be a sleeper pick for this.

Lu Dort undrafted rookie into best perimeter defender on a 67 win championship team

Half the beat teams the last 5 years

Giannis is the correct answer and it’s not close tbh

LeBron James - no one saw it coming

Raja Bell was cut by the Spurs before going on to having a great career

Would you consider Tony Parker and Manu Ginobili as projects or just lucky draft picks?

Peyton Watson barely played in college and now is on his way to become a good starting level player 

Jokic

Shawn Kemp. Sure, he was a McDonald’s All-American, but was mainly a super athletic freak and nothing else. He also never played in college and went straight to the NBA. Everyone thought the Sonics were nuts taking him in the first round (#17). The next year, they drafted Gary Payton, hired George Karl a couple years later, and the rest is history.

Dirk was the reason so many raw Euro guys got drafted in the lottery and flamed out. He was traded and had a poor rookie season, but the rest is history

I’ll go with the undrafted hall of famer, Ben Wallace.

He wasn’t terrible in college but it was a D2 school so I think he fits the criteria.

I’m still waiting on Anthony Randolph to put it all together. It’s not too late

Dewayne Dedmon averaged 7.1 ppg, 6.3 rpg, and was 0-4 from 3 in two years at USC.

After not being drafted, he averaged 6.3 ppg, 5.8 rpg, and shot 34% from 3 in a ten-year NBA career with 10+ ppg in years 5 and 6.

Cuttino Mobley, drafted 41st (although in 1998 he missed taking Rhode Island to the Final 4 by 2 points)

To me a project player is someone who clearly has very high potential but isn’t ready to contribute in the nba at the beginning of their career. The best examples of that would be Kobe and Giannis.

If you’re just looking for players who weren’t as good in their league before the NBA, Westbrook and booker both came off the bench and Kawhi couldn’t shoot. Giannis is probably still the best answer considering he was playing in a second tier Greek league nowhere near the best competition in Europe.

After Giannis? Toni Kukoc or Jimmy Butler

Jimmy Butler comes to mind

Giannis, Jaylen brown, kawhi

Elmore Smith. Wouldn’t call him a superstar, and he was drafted 3rd. But he basically developed into an NBA caliber player in college. He was a 7 foot dude who barely played in high-school due to not knowing how to shoot or dribble.

Not Brook Lopez in how you are talking about projects, but still give it a shout for basically turning all your weaknesses into strengths.

Embiid was a project for sure. Was always hyped for potential but barely played because of injury, when he finally hit the court he was explosive

Zach Lavine. Dude didn’t start in college. I remember when he was drafted everybody said it was for the upside due to his athleticism and he turned out to be better than the #1 pick on the same team (Wiggins).

Jermaine O’neal until his injuries mounted.

Right now, Jaylen Brown looks like a pretty good answer.

Averaged 15 in college, but was still seen as a project guy with a small chance of panning out - at least immediately. Him being the #3 pick was mostly derided and widely panned, especially amongst the Celtics fan base.

Won FMVP, EFMVP…

Currently looking like a top 10 guy while he’s carrying a team missing a top ~5 guy.

I think even those that were super high on his potential entering the draft didn’t think his ceiling was this high.

Derrick White

Austin Reaves

Dennis Rodman

MPJ imo. Barely any play time for his first 2-3 seasons, and is now a champion and #1 option on a team after being traded