Building something that lasts in the NBA is hard. Even teams on top live in fear of one butterfly flap that might undo everything -- one injury, one trade gone bad, one unhappy player or even a blip of bad timing in the way contracts are staggered.

It's amazing how fast things spin out of control, and how long it can take a team to find its bearings again. Teams crave control. They hoard draft picks to decide who gets to wear their uniform and craft five-year plans that make them feel and act as if they are a step ahead. Sometimes they really are! Play a couple of things wrong, and suddenly you're reactive and desperate, flailing one move behind everyone else.

The Dallas Mavericks busting up their 2011 title team to chase free agents wasn't on its own a mistake. Those dudes were mostly fogies, and Tyson Chandler, the one core guy at the outer edge of his prime, has been up and down since signing with the Knicks. You can't control a free agent's choice, especially when incumbent teams can outbid you, but it wasn't nuts to think some big name would take the Mavs' money -- particularly given Mark Cuban's cozy relationship with power agent Dan Fegan.

But the Mavs have mishandled most of the things they do control. They traded down in drafts to save money, traded out of them and whiffed on most of the picks they did make. Donnie Nelson, the team's GM, begged Cuban to draft Giannis Antetokounmpo at No. 13 in 2013, but the Mavs instead traded down five spots to open up a few hundred thousand bucks in extra cap space for Dwight Howard. They ended up drafting Shane Larkin at No. 18 as part of a deal that sent away their first-round pick from the year before.

Fewer teams had cap room then, but the Mavs could have picked 13th and found other ways to dump money in a pinch.

Team building is hard, and it requires major luck somewhere along the way. Most picks below the lottery yield back-of-the-rotation guys or total busts. But to sustain success, you eventually have to hit on a few of them. Roddy Beaubois, the No. 25 pick in 2009, might have turned into a hit had foot injuries not ruined his career. Justin Anderson, the 21st pick last year, looks like a hoppy and versatile wing perfect for the modern NBA. The hits don't have to be Kawhi Leonard at No. 15, or Draymond Green in the second round. One or two Jae Crowders will do.

The Mavs had the real Jae Crowder, and included him (plus this year's pick) in their ill-fated gamble for Rajon Rondo. Boston got Brandan Wright in that deal, too. Crowder and Wright will earn $12 million combined next season, about 60 percent of Kent Bazemore's likely salary. Dallas was brilliant to snag Al-Farouq Aminu on a minimum salary in 2014-15, but then let him walk to Portland to carve out max cap space for DeAndre Jordan.

Dallas sacrificed a lot of good under-27 players in the pursuit of great ones, and the odds got worse when the cap boom gave everyone space. Chandler Parsons is the latest such casualty. He went from bro-in-chief to outcast in record time, and no one will say exactly why. His knee issues certainly frustrated the Mavs, especially given the timing of flare-ups; Parsons appeared in just one of Dallas' 10 playoff games over the past two seasons.

The Mavs' decision that Parsons is no longer a max player offended him, and the market has proved Parsons right; Memphis has offered him a max contract pending a physical that promises to be one of the most suspenseful moments of this free-agency period.

Parsons didn't find a groove in Dallas until January, and he's a minus defender. But he's a high-IQ guy who shot 39 percent from deep in Dallas and can shoot, pass and dribble across both forward spots. He's never made an All-Star team, and he's not a foundational piece. No one knows how his right knee will hold up going forward

But Parsons is good, and the Mavs can't afford to let good 27-year-olds walk away without a Plan B. Their Plan A appears to have been a double-barreled signing of Mike Conley and Hassan Whiteside, but that left them once again at the mercy of variables they cannot control. Stud free agents want to see players with whom they can grow, but the Mavs have mostly punted on such players to pursue stud free agents.

We know by now what Plan B is: Dallas has a list of canny veteran free agents they can nab after everyone has picked over the market, and they will mesh better than any of us expect. Dirk Nowitzki is a rising tide on offense, and Rick Carlisle is one of the greatest coaches in NBA history.

It is hard, and perhaps impossible, to bottom out when you have someone as great as Nowitzki. Maybe it is time to try, one way or another. Before the Jordan hostage situation a year ago, Cuban said he had planned to tank had Jordan spurned Dallas. It's unclear how he'd have done so without ordering Nowitzki to have some long-overdue surgery, but perhaps it's time to do it now.

Like it or not, that is a tried-and-true path you can control: lose a lot of games and take a shot at drafting a superstar. That is why Sam Hinkie scorched the earth in Philadelphia -- to eliminate as many of those noisy variables as possible, and draft over and over in the spots with the best chance of turning out a Nowitzki.

You can get superstars without doing that, of course. The Mavs drafted Nowitzki at No. 9. The Spurs turned George Hill, the No. 26 pick, into Leonard, and leveraged Leonard into pole position for LaMarcus Aldridge. (Still: Ground zero of the Spurs dynasty was a blatant tank job that netted one of the half-dozen greatest players who ever lived). The Rockets transitioned from Yao Ming to James Harden while fighting for the playoffs every year.

But that middle road is hard, and it requires maximizing every asset --- drafting well and keeping the cupboard stocked for deals. It's why Sam Presti in Oklahoma City keeps turning outgoing stars into younger players and extra draft picks. He knows he can't afford to be left with stars and nothing else. He wants things he can control -- draft picks, younger players on rookie contracts, matching rights. They are hedges against the unknown, a future he can sell to Kevin Durant and Russell Westbrook.

The Mavs don't have that, and they are running out of time for Nowitzki. Set emotion aside and it's probably best for them to part now. Nowitzki can chase one last ring, and the Mavs can bottom out ahead of a loaded draft in a year when everyone else is trying to win. It probably won't happen -- city and player care for each other too deeply -- but it would be the quickest path to a new foundation.

The Knicks have their foundation, Kristaps Porzingis, and maybe that is all that matters. For now, Carmelo Anthony is almost their own, younger version of Nowitzki. He's so good, they can't properly rebuild. Provide Anthony an average supporting cast and you'll be around .500. Fail to do so, and all you have is a miserable superstar.

The Knicks and Anthony are stuck with each other. The deal he signed in 2014 has a no-trade clause, and a suitor both acceptable to Anthony and stocked with assets the Knicks want just hasn't emerged. There was some internal hope the Cavs might become that team, but then they won the whole stinking thing.

Even had the Knicks wanted to trade Anthony before re-signing him, the timing never broke right. Two years before the expiration of his deal in 2014, the Knicks won 54 games and snagged the No. 2 seed; no team would ever trade its star during a season like that. New York predictably slipped the next season, 2013-14, but Anthony was on an expiring contract by then, torpedoing his trade value.

And so he were are, in 2016, with the Knicks building a team designed to make the 2012 conference finals. They've made a choice: as long as Anthony is in New York, they are going to try to at least be competitive. The Knicks don't really even see another choice. They might feel differently had they not traded so many picks and players in previous win-now moves, including the disastrous Andrea Bargnani deal. They don't have a lot of tools beyond money and a big city.

Each of this summer's moves is defensible on its own. They flipped Robin Lopez and Jerian Grant for Derrick Rose because the organization needed a galvanizing spark, and because the free-agent market is thick with centers to replace Lopez -- and thin on point guards better than Rose. OK, fine. If things go badly, the Knicks let Rose walk.

They're about to sign Joakim Noah to a four-year, $72 million deal despite knee and shoulder injuries that have cramped Noah's game since a magical 2013-14 season in which he finished fourth in MVP voting.

Again, fine. The Knicks need leadership and defense, and they are not really getting those things from any of their veterans. Noah is a beloved teammate, and he will help a defense that has been wretched almost every season since the Jeff Van Gundy era ended. He can spare Porzingis the brutality of playing center full time, cede the position to him for 10 or 15 minutes per game, and slide into a backup role whenever Porzingis is ready to start in the middle.

Noah can facilitate from the elbows and resume setting nasty screens for his old Chicago point guard. He started looking like his snarling, rebound-munching self again in the month before his shoulder gave out last season. He even made some layups. Noah is hungry to prove he can rediscover his peak form, and even 85 percent of that player is damned good.

None of these players is ancient, either. If Porzingis makes a leap in Year 2 or 3, the start of his prime might overlap with the very end of those of some other New York players.

But zoom out and the vision is murky. Are the Knicks going to run any triangle with Rose, a non-triangle point guard, spotting up in the corner? Are they a fast-break team? Even if they sign another wing shooter -- Courtney Lee, Eric Gordon -- can they provide Melo enough space to rampage on the block with Noah and Rose clogging things up?

If they do end up with Gordon, the collective health risk between Rose, Noah, and Gordon is enough to induce some panic dry-heaving.

When the Knicks flipped Lopez for Rose, fans crowed about how much cap space New York could open for next summer's insane free-agency class. But Lopez turned into Noah on a richer long-term deal, and if the Knicks commit $30 million combined in 2017-18 salary to Noah and Shooting Guard X, they might have only between $30 million and $35 million in cap space next summer -- enough for one mega-max but not for the dream scenario of two.

That estimate includes $0 for Rose. He is a risk-free flier primed for a contract year, but that's exactly why Chicago traded him: to avoid the temptation of investing more in Rose's knees after one good season.

There is a lot of uncertainty between now and next July. The cap for 2017-18 probably will come in higher than the projected $107 million. New York could off-load Kyle O'Quinn, Langston Galloway and any free agent it signs now.

But in the bigger picture, the Knicks are using equity to get these guys: a good center on a value contract (Lopez), a semi-interesting point guard prospect (Grant) and cap flexibility. They haven't boxed themselves in, but they have exhausted assets they could have used in gain-an-inch moves that might have primed them for something bigger -- something that better fit Porzingis' timetable.

With Anthony around, they are not going to wait for Porzingis. But there were better ways to straddle the middle ground while still gathering goodies on the fringes that could pay off down the line.

Again: Maybe all that matters is that they drafted Porzingis. Any team hoping to get anywhere needs to find a young star somehow. The Knicks have one. The Mavs barely have anyone young. Even for smart teams with good intentions, the NBA can be a hard place.