There are only three ways you really get better in the NBA. You trade for upgrades, you sign upgrades in free agency, or you improve internally.

You're going to mention the draft, and let me stop you before you do. No team really adds a draft pick and makes a leap in playoff contention that first year. Yes, the Wolves were better than the year before because they added Karl-Anthony Towns, but Towns is very much an exception -- and still the Wolves only won 29 games last season. The Cavaliers missed the playoffs in LeBron James' first season. It's just rare that any team undergoes a major transformation with the addition of a rookie.

Now, the development of that rookie over time, that's internal improvement.

Look at a team like the 2014-15 Warriors, who went from a No. 6 seed and first-round bounce the previous season to an NBA championship based almost entirely on internal improvement. They didn't go out and sign big-name guys. They chose to keep Klay Thompson -- in the interest of cohesion, chemistry and allowing the team to continue growing together -- when a trade was reportedly on the table to acquire Kevin Love.

Stephen Curry got better. Thompson got better. Draymond Green got better. They changed their lineups. Changed Andre Iguodala's role. Changed their offensive philosophy under Steve Kerr. And the additions they did make (Shaun Livingston, LeAndro Barbosa) were in keeping with this kind of consistency and prioritizing of internal growth.

This year, there are four teams taking a decidedly similar approach. They all have legitimate, young talent to build upon. and while a Warriors-like leap is asking way too much, there is good reason to believe these four teams are making the right call sticking with their guys and should see the benefits down the road -- some sooner than others.

Portland Trail Blazers

On paper, the Blazers did make some fairly big free-agent acquisitions this summer, adding Evan Turner on a $70 million deal and grabbing Festus Ezeli from the bargain bin. But don't get caught up in the money, particularly Turner's. These are not franchise-altering guys by any stretch. They are merely support for the core group Portland clearly believes in building around.

Damian Lillard and C.J. McCollum are obviously the guys here. Turner, a versatile playmaker who can handle the ball, can take some pressure off them, but Portland will develop, and ultimately improve, as much as this dynamic backcourt does.

Lillard had a bounce-back season last year. A glaring defensive weakness in 2015, last season he managed to at least hold his own, though he's still a long way from being a plus on that end. But Lillard is always going to make his biggest difference on the offensive end, and there he was terrific last year, securing the best assist figures of his career despite the departure of four starters. We know Lillard can score. We know he's probably the biggest off-the-dribble threat from deep this side of Curry. The assist figures, however, show Lillard's improvement as a playmaker and game manager.

McCollum, on the other hand, won Most Improved Player, and became a legit primary threat offensively. But for the Blazers to take the next step and really threaten for a top-four seed in the Western Conference, they need more than improvement from Lillard and McCollum. Al-Farouq Aminu, Meyers Leonard, Mason Plumlee, Alan Crabbe, Mo Harkless -- these are all players that the Blazers have committed time and resources toward as part of this core.

Damian Lillard is the leader of Portland now. Getty Images

Lillard and McCollum improving, both together and individually, is expected, and it's reasonable to anticipate lineups that include those two getting better merely for their presence. The question is about the other guys. What is their ceiling as individuals? How much will the continuity help?

The Blazers got career seasons out of nearly all these support pieces last year, with Aminu, historically a non-shooter, putting up a 36-percent mark from beyond the arc. With so many players having exceeded expectations last year, is it reasonable to anticipate that happening again?

This is where the moves GM Neil Olshey made in the offseason pay off. If Plumlee, Leonard, and ever-a-prospect Noah Vonleh are unable to validate the optimism, Ezeli is there as a fallback. If Crabbe or Harkless struggle, Turner provides a different look to boost various lineups.

As long as the multiple homegrown bets Olshey has put on the roullette board come in at a decent rate, the Blazers will at least be as good as last season, and if they all hit like they did a year go, they'll actually improve -- though that improvemnt may not be completely reflected in the win total. It's not hard to envision a better Portland team winning roughly the same amount of games -- 43 -- which may or may not be good enough for the fifth seed again.

It should be noted that outside of a blistering 18-7 run in January and February, Portland went 26-31 the rest of the season.

Denver Nuggets

The salary floor -- basically the lowest amount of money a team is allowed to spend on its players this coming season -- is $84.73 million. As of right now, the Denver Nuggets have just $75.7 million in guaranteed money on the books and their roster is effectively set. Most likely they'll have to distribute that extra $9 million and change to their current players.

The point? Denver did not add a lot of new talent this summer.

Given their market, performance last season (33 wins) and the absence of a true superstar, it was always going to be tough sledding getting quality free agent upgrades to Denver. Rather than throwing a bunch of money at a subpar player, as so many other teams did this summer, the Nuggets made just one substantial play in going after Dwyane Wade, who, despite shunning the Nuggets' interest to sign in Chicago, came away very impressed with the organization.

The Nuggets, of course, are hoping D-Wade is right about their future, which no doubt rests on the shoulders of a promising, if heretofore unaccomplished, core of Emmanuel Mudiay, Gary Harris and Nikola Jokic. That said, those guys are not a cure-all. There is no definitive star in Denver. The shooting woes are real. And inexperience is everywhere.

Mudiay, who had the biggest profile entering last season yet struggled the most, has to be better, and he showed flashes toward the end of last year that suggest he'll be able to do just that. Over his last 22 games, Mudiay scored in double figures 19 times, and had five or more assists 12 times.

Mudiay's biggest issue, surprisingly, wasn't his miserable jumper (though he did wind up with the ninth worst effective field goal percentage of any rookie playing 20 minutes a night in the shot-clock era). It was his handle. It was loose, high and sloppy. Opposing point guards jumped all over it. But by season's end, it was largely corrected and that helped him thrive.

In all likelihood, we won't see a huge improvement in Mudiay's jumper this year. What should get better is his finishing ability, confidence to attack in transition, defense, and control of the game.

Gary Harris is likely the second- or third-best player on the team, drifting somewhere with Danilo Gallinari and Jokic in whatever order you want. He's a relentless defender, smart and instinctive, a crack shooter who finally started to understand NBA spacing and flow last year, and he seemingly added something new to his game every night.

Taller guards were able to light Harris up from 3-point range, so halfway through the season he started attacking their catch and the motion they would use to bring the ball up, without fouling, to disrupt them and force them to reset the ball to someone else. Little things like that are what internal improvement are all about. Harris is primed to gain the most attention this year as he hopefully continues on the path he's already been on but perhaps hasn't been sufficiently noticed for.

After his nice Olympic showing, Jokic is coming in with the most hype. He's a good-natured kid they call 'Joker' in the locker room, and he carries with him an incredible skill-set which was on display when he scroed 25 vs. Team USA in the Rio. He's shown much of the same ability as a young Marc Gasol without the defensive intensity. Amazingly, most of the offense for Denver needs to be run through the 21-year-old, if for lack of options, so these skills are only of increased importance. His passing ability combined with his touch and innate scoring ability make him perfect as a focal point for the rest of Denver's slashers.

Nikola Jokic, Olympics
Nikola Jokic came up big in the Olympics. USATSI

So that's the core Denver will look to improve with, and they have other players who should show more after a year in Malone's system. Will Barton put up great stats, though the impact could be better. If Gallinari can learn to trust the younger guys, they should open up more opportunities for him. Jusuf Nurkic remains a promising behemoth whose raw size can change the game. And maybe most importantly, the Nuggets get back Wilson Chandler, who missed all of last season with injury. Chandler, a perfect stretch four, gives them a lot of lineup flexibility.

All of this said, there's a risk of Denver becoming Orlando 2.0, a group of young, good-not-great players that can't put together a cohesive performance night in and night out. Mudiay's shot won't be anywhere near good, Harris will still be 6-3 at shooting guard, and Jokic will still lack the kind of strength you need vs. the biggest and baddest. Any injury to a core player could cause the whole house to come down, and they play in the toughest division. Denver chose not to take unnecessary risks and trust the core, but the core has to show this year that they're worth attaching a future to.

Minnesota Timberwolves

Karl-Anthony Towns. Andrew Wiggins. Zach LaVine. Gorgui Dieng. The Wolves are bursting with promising talent, and Towns alone is enough to make you think they'll improve on last year's 29 wins.

Towns' ceiling is seemingly infinite. It's like trying to guesstimate the height of the northern lights. He could be anything next season under Tom Thibodeau: a growling, snarling post-up monster that can wipe small-ball off the floor and send fans of the "modern" game scurrying underground from his wrath. He could be an advanced version of a stretch five, knocking down 3-pointers regularly in the pick and pop, and then driving past defenders desperate to contest. There are very few things Towns can't do on a basketball court. He's terrifying.

Wiggins is the more fascinating one, because you aren't as sure what he'll become. Will he become efficient? Will he become a facilitator? Could he maybe rebound once in a while? Will he become a more complete player, or is he destined to be in the same mold as Rudy Gay and DeMar DeRozan -- jump-shooting wings who are athletic and can dunk really impressively, but never contribute more? Will his defensive metrics catch up with his defensive ability? Wiggins, too, could be anything, it's just that right now, he's not anything more than a pretty good basketball wing, vs. Towns who already is so many awesome things immediately. This is a huge year for Wiggins.

Andrew Wiggins Karl-Anthony Towns Wolves
Are the Wolves youngsters ready to win? USATSI

LaVine showed real promise last year and if Tom Thibodeau abandons the experiment of putting him at point guard and lets him use his combo-guard abilities to their fullest, he could really cement a role on this squad. Dieng struggled last year, but if Thibodeau molds him into the kind of defensive force he can be, look out.

Then there's Ricky Rubio, who could be traded, and some other components, but it's really those four, and honestly just those top two. The nice thing about the Wolves is they don't have to second guess themselves. They banked this season on a better coach getting more out of the most talented young core in the league. If they miss, it will be because of circumstance or inexperience, not from a flawed assessment or design.

Milwaukee Bucks

The Bucks took a huge leap forward in 2015, and then a major tumble in 2016. The Greg Monroe signing didn't work out. Good idea, just didn't pay off. The defense crumbled to bits without the veterans like Jared Dudley and Zaza Pachulia around.

Entering 2016-17, there's really one story for the Bucks: Giannis. The Greek Freak Giannis Antetokounmpo is still without definition and is working on his fourth iteration in terms of role. Now it seems he'll be point guard and center simultaneously. The best way to think of Antetokounmpo is like Justin Timberlake's rendition of Sean Parker says in "The Social Network."

"You don't even know what the thing is yet," Parker says of Mark Zuckerberg's creation, Facebook.

That's Giannis. We don't even know what he is yet. He could be a dominant big man who finishes inside, controls the paint, and is some sort of extrapolation of Amar'e Stoudemire. He could be the true point forward that people have looked for over the past decade, as guys like Anthony Randolph and Tyrus Thomas fell by the wayside. Or he could just be a more raw Andrei Kirilenko, able to do a lot of things well, but no one thing at a dominant level.

This season will likely tell us a lot about the Freak, because the Bucks are building their future around him. He is the focal point of the team.

Giannis Antetokounmpo hopes to lead the Bucks forward next year. USATSI

There are other young pieces, too, that they're banking on. The Bucks continue to make Jabari Parker into a traditional (and unimpressive) power forward despite his considerable (and impressive) perimeter abilities. This is probably the last run of the Michael Carter-Williams experiment in the NBA, which is stunning for a one-time Rookie of the Year candidate, but if he starts to get it and has a Chauncey-Billups-like belated take-off, look out.

The Bucks have stacked the roster with young wings who can shoot, and then there's Khris Middleton.

Middleton was a second-round pick who came out of nowhere and now is maybe the best value 2-guard on the trade market (if there is indeed on the trade market, which the Bucks don't seem to be very clear on). Middleton is an efficient shooter who defends well in half-court situations (his transition defense is a nightmare) and comes with very little downside.

However, he also just turned 25 in August. Players don't traditionally make huge jumps in terms of skill improvement after age 25, but they do come into their own, and Middleton looks very much on track there. He's the X-factor for this team. If he makes a leap into the conversation for top-five shooting guards in the league, Milwaukee looks much different.

And so, to recap: All of these teams above have an element of the unknown. But we mostly know that the Blazers are a guard-centric playoff team with a great coach. We mostly know that the Nuggets are low on star power and high on quality basketball players and effort. We know that the Wolves are the most inexperienced but also the most talented of the group.

Milwaukee we know very little about. Do they make a leap back? Was 2015 a bizarre outlier? Is Antetokounmpo a superstar lying in wait, or another jack-of-every-possible-trade-master-of-none? This is what makes Milwaukee interesting this season. They have a lot of potential, but potential, as the saying goes, gets coaches fired. They're a puzzle of unsolved ability, and something, or someone, needs to put it together.