Long-term upside is another way of talking about a prospect's ceiling.
A ceiling is the best possible player a prospect can become. But it usually takes a while to get there, which is why we call it long-term upside.
Though these players have the highest ceilings and upsides, it doesn't mean they are the six best prospects. Victor Oladipo is likely to get selected before Alex Len, though if they both reach their ceilings, Len will end up the better player.
These are the guys who could turn out to be the top players from this draft if they all reach their NBA ceilings.
Nerlens Noel has the chance to be that defensive game-changer. The guy who forces opposing coaches to modify their game plans.
His defensive instincts are off the charts. When you combine his ability to anticipate with his size, length and athleticism, you get a rim security guard that's awfully tough to get by.
Offensively, Noel is more effective than he's given credit for. Though raw as a scorer, his physical tools allow him to pick up easy points on a routine basis. It's tough to contest some of his shots when they're coming from two feet above the rim.
Upside doesn't necessarily have to equal 20 points a game. It can be related to impact, and you don't have to score to make a difference. Roy Hibbert has been a good example of that recently.
If the Cavaliers select Noel No. 1 overall, it's because they believe he can be their interior anchor for the foreseeable future.
Ben McLemore has that lethal blend of long-range accuracy and explosive athleticism that NBA guys eat up.
You just can't go wrong with that combo. McLemore can get you easy buckets as a cutter, finisher in transition and spot-up threat from behind the arc.
And that's a worst-case scenario.
If McLemore improves his in-between game, dribbling and shot creativity, we could be looking at one of the few potential All-Stars this field has to offer.
Right now, McLemore's ceiling would reflect that of an elite complementary scorer. You never saw Ray Allen in isolation, and McLemore is the same way. He's going to get his points running off screens, spotting up, slashing and on fast breaks.
Plus, he's got the tools to be a defensive asset on the perimeter.
Assuming all goes to plan, McLemore should be a long-term starter in this league.
You won't find too many 6'6'' point guards out there. Not natural ones like Michael Carter-Williams, anyway.
He's a pure, pass-first facilitator with the size and athleticism of a wing. Logic tells us that's a deadly combination.
Carter-Williams finished No. 3 in the country in assists before leading Syracuse to a Final Four appearance. He's crafty off the bounce with the ability to get into the paint and make plays over the defense.
An inconsistent jumper is currently holding him back, but that's a fixable weakness with the right mechanics.
By the time he's learned the ropes and his jumper is a threat, Carter-Williams could end up being one of the tougher assignments in the league.
Anthony Bennett's long-term upside is what drives his appeal in this draft.
He's got the most potent package of athleticism, explosiveness and agility. Bennett isn't a guy you want to take a charge from when he's got momentum attacking the rim.
There is some risk with Bennett. At 6'8'', he's undersized to play his natural position as a 4 exclusively, but with imposing strength and a monstrous wingspan, Bennett has features that help make up for an inch or two vertically.
With the ability to overpower big men inside and beat wings off the dribble, Bennett has the chance at being a difficult frontcourt mismatch. The Larry Johnson comparison is on point.
He'll need to avoid falling between positions. If Bennett struggles to finish down low or create offense on the perimeter, the tweener label is sure to surface early in his career.
But I wouldn't bet on it.
Bennett can hit his ceiling if he finds a way to exploit the advantages his physical tools present.
The only defense for a 7'1'' scorer in the post is a double-team. And if you're Alex Len's coach, that's exactly what you want.
Given his size and length, there aren't many people out there who can contest his shot. He still has to work on getting his shot off, but if the delivery to his move runs smoothly, chances are he'll have a clean look at the rim.
Len is a multidimensional threat from that elbow-to-baseline area. He can square up to the rim for a jumper, face it and attack his defender off the dribble or play back to the basket and score over the shoulder.
The most important thing is putting himself in position to actually do these things, but the more reps he gets, the more comfortable he'll become.
Len has one of the higher ceilings in the draft as a frontcourt mismatch. If you can find a center who commands routine double-teams, it will just create more opportunities for everyone else.
If we're talking long-term upside and the highest possible ceiling, you have to give Giannis Antetokounmpo a mention even if you can't pronounce his name.
He's got 6'9'' size with a legit point-guard handle, and that doesn't change whether he's playing in Greece's second division, the NCAA or my grandpa Paul's recreation league.
What he learns to do with that handle will determine how far he goes.
It's going to take him a few years in the league just to understand the game and a few more after that to apply what he's learned.
Antetokounmpo has drawn comparisons to Nicolas Batum and Scottie Pippen, two versatile forwards who can create from the wing and pass off the dribble.
However, we're talking really long-term here. You might look like a completely different person by the time Antetokounmpo gets a chance to reach his ceiling.