The NBA is considered the holy grail for basketball – so why have so many high caliber players over the years turned down the chance to enter the biggest league of all?

With this year’s March Madness tournament approaching, college players across the country are once again hoping to make an impression on NBA scouts. According to the latest March Madness betting odds, Gonzaga, Baylor and Michigan are the big favorites to win the tournament outright, although with Baylor recently suffering their first loss of the season against Kansas, their confidence could be shattered.

Michigan are one of the great college sports success stories, with 61 players drafted into the NBA over the years. This year, all eyes are on Hunter Dickinson, the 7’2 freshman who has so far picked up four freshmen of the week accolades in his college career. He’s averaged 15.1 points and 7.2 rebounds for the team this season, with the 20-year-old center seemingly a dead cert to make the transition to the big league.

He has competition from 19-year-old Cade Cunningham at Oklahoma State, one of the country’s best freshman players, who was largely responsible for helping his team hit a five-game winning streak. The star forward hit 52.2% of his shots from the field and averaged 22.2 points per game during this crucial final stretch.

But this season, Gonzaga are the big success story, entering March Madness as the first unbeaten team since Kentucky in the 2014-15 season, with 28 consecutive wins under their belt. The whole team has been put under the spotlight, but 6’7 senior wing Corey Kispert (averaging 19.5 points) and Florida transfer Andrew Nembhard, who has made a major impact in recent games, are two to keep an extra eye on.

Not every player dream of making the transition to the NBA, with some of the best players in the history of basketball uninterested in joining.

None of these names are more prestigious than “the Holy Hand” Oscar Schmidt, who turned down repeat offers from the NBA to stick with his national team in Brazil. With 49,703 points scored in his career, nearly 12,000 more than Kareem Abdul-Jabbar, and this isn’t the only stat that makes him the best player to have never played in the NBA. He played in 38 separate Olympic matches between 1980 and 1996, totalling 1,093 points – the highest scorer in Olympic basketball history.

Similarly, Nikolaos Georgalis rejected contracts to play for the Boston Celtics and New Jersey Nets because it would have made him ineligible to play for his beloved Greek national team. In Greece, he became the country’s greatest ever player, winning five Most Valuable Player awards and eight league titles, with a 31.2 point average over his entire career. An urban legend poses that he even beat Michael Jordan by 50 points in 1983, in an exhibition against his North Carolina college team.

“Pee Wee” Kirkland is another such player, who legend has it even turned down an offer to play for the Chicago Bulls because he was earning more as a drug dealer. His talents on New York’s playgrounds made him a desirable player for coaches across the country, with UCLA coach John Wooden wanting him on his team, hoping to pair him up with Kareem Abdul-Jabbar and prove an unstoppable force. But he instead signed with Norfolk State, before being incarcerated. In prison leagues, he is rumored to have scored more than 100 points in several different games.

And then there are the several tragic “what ifs”; the players who died before they got a chance to play, or even get drafted.

Of these, no legend is more renowned than that of Earl Manigault, the combo guard who became something of a legend on New York City courts. Kareem Abdul-Jabbar would agree, famously saying that “The Goat” was the best player he ever faced, and Manigault’s legend has mostly been forged by the ease with which he beat the NBA’s best player. But although his life story got turned into a movie, he never got a chance to shine in the NBA, sadly passing away at 53.

And then there are the “what if” stories that never got a chance to prove themselves when drafted. Small forward Len Bias was drafted to the Boston Celtics back in 1986, earning comparisons to the then ascendant Michael Jordan, with hopes he’d be a shot in the arm for the ageing team. Tragically, he was found dead at his home just 24 hours after he’d been signed, with the superstar in the making never getting his chance to shine.

There are several players with serious potential to transition to the NBA following this year’s tense March Madness tournament. But only time will tell if they’re legends in the making, or tantalizing “what ifs” who will never have a chance to match their early potential.