NBA free agency can make or break an organization for years.

If a team commits a significant portion of its cap room and roster flexibility to one player who winds up performing at a below-average (or worse) level for the life of the contract, it can be difficult to overcome.

On the other hand, a steal like the Miami Heat's Duncan Robinson can change fortunes for the better. He's under contract for just $1.7 million next season after boosting Miami's net rating by a whopping 13.7 points in 2019-20.

We'll save the feel-good stories for another day, though. This is about the former bunch. Which free-agent signings from the last 10 years were the biggest mistakes?

It's hard to come up with a rigid, objective set of criteria to determine the answer to that question. So, we'll look to a number of objective factors to make a subjective determination.

How did the player perform in the season or seasons preceding the deal? How old was he? What kind of production did he provide during the life of the contract? Did he even play for the length of the deal? Did he fit on the team that signed him?

We've seen plenty of head-scratchers over the years, but these five were the worst.

Dishonorable Mentions

There was no shortage of options for this slideshow, thanks in large part to the unforgettable summer of 2016, when a spike in the salary cap gave teams more flexibility than they knew what to do with.

Some other doozies are sprinkled throughout the decade, though. And the jury's still out on a handful of current deals.

Solomon Hill (4 years, $48 million in 2016)

This was somewhat defensible at the time. Hill was coming off an age-24 campaign in which the Pacers were significantly better when he played. If his three-point shot ever came along, it looked like he might be a solid 3-and-D player. And $12 million a year wasn't egregious in comparison to other salaries doled out in 2016.

J.R. Smith (4 years, $57 million in 2016)

Keeping the title-winning Cleveland Cavaliers intact following their unlikely 3-1 comeback made sense, but at 31 years old, Smith entered the 2016-17 season with only one marketable skill left: a three-point shot that largely abandoned him over the life of this contract.

Brandon Knight (5 years, $70 million in 2015)

Injuries derailed a once-promising career for Knight, who averaged 17.0 points and 5.2 assists while shooting 38.9 percent from three in the age-23 season preceding this deal.

Dion Waiters (4 years, $52 million in 2017)

Waiters had, by far, the best season of his career in a contract year in 2016-17. Even then, he was a below-average player, according to box plus/minus.

DeMarre Carroll (3 years, $21 million in 2019)

You might think Carroll is here for the four-year, $58 million deal he got from the Toronto Raptors in 2015, but it's actually the follow-up that deserves a mention. The San Antonio Spurs not only signed Carroll to this deal, it was part of a sign-and-trade that cost them one of the league's best shooters (Davis Bertans). And Carroll was bought out less than a season in the contract.

Luol Deng (4 years, $72 million in 2016)

After nearly a decade of playing under grinding coaches like Scott Skiles and Tom Thibodeau, Deng showed signs of decline in Miami. And then the Lakers threw $72 million at him ahead of his age-31 season. He was waived just over two years later.

Allen Crabbe (4 years, $75 million in 2016)

In theory, Crabbe should've been a solid 3-and-D rotation player, but he never moved the needle much on defense and the Portland Trail Blazers paid him like a no-brainer starter.

Joakim Noah (4 years, $72 million in 2016)

Like Deng, Noah's legs had been through Thibs' ringer. This kind of commitment heading into his age-31 season was beyond bold. And the New York Knicks wound up waiving him just over two years later. When he can actually get on the floor, though, Noah has shown he can still contribute.

Zach Randolph (2 years, $24 million in 2017)

Heading into his age-36 season, the Sacramento Kings signed Randolph to be one of the veterans who would usher in a new era the youngsters clearly weren't ready for.

Al Horford (4 years, $109 million in 2019)

Horford may still have a bit to give, but the fit with the Philadelphia 76ers was so colossally bad that his contract has rapidly become one of the league's albatrosses. 

Chris Paul (4 years, $159.7 million in 2018)

CP3 is a first-ballot Hall of Famer, but this much time and money ahead of his age-33 season was an all-in bet that didn't pay off. When things went sour between Paul and James Harden, the Houston Rockets had to attach two first-round picks and two first-round pick swaps to unload the deal to the Oklahoma City Thunder and take on another burdensome deal (Russell Westbrook's).

Whew... Without further ado, let's get to the bottom five.

5. Evan Turner (4 Years, $70 Million from the Portland Trail Blazers in 2016)

Evan Turner was actually coming off a decent season in 2015-16 before he signed his monster deal the following summer.

As the Boston Celtics' sixth man, Turner averaged 10.5 points, 4.9 rebounds and 4.4 assists (13.7 points, 6.4 rebounds and 5.8 assists per 75 possessions).

In theory, his playmaking from the wing made sense alongside Damian Lillard and CJ McCollum. Perhaps it could've been like a smaller version of the Draymond Green-Stephen Curry-Klay Thompson dynamic.

The red flags were waving on this one, though.

That season with Boston was the first of Turner's career in which he put average production (exactly average, actually), according to box plus/minus. And his shooting remained a major problem in an era where shooting was becoming ever more important.

During his first couple seasons in Portland, Turner had far fewer opportunities to create. And a plummeting assist percentage accompanied a decline in overall impact.

The Blazers allowed him to create more in the third year, but an inability to space the floor still hampered him.

He was traded to the rebuilding Atlanta Hawks ahead of the last year of the deal, where he appeared in just 19 games during 2019-20.

Over the life of the contract Turner signed in 2016, his minus-1.1 wins over replacement player (value over replacement player times 2.7) ranks 773rd among the 864 players who've appeared in an NBA game.

4. Bismack Biyombo (4 Years, $70 Million from the Orlando Magic in 2016)

The case for signing Bismack Biyombo to a four-year, $70 million deal was pretty simple. He was coming off an age-23 season in which he looked like a defensive force in the playoffs.

He was third among Raptors in 2016 postseason wins over replacement player, thanks to averages of 9.4 rebounds and 1.4 blocks in just 25.3 minutes per game.

But $17 million per year (nearly a fifth of 2016-17's salary cap) for a player who'd never produced at an average level and adds little to nothing on offense seemed like a stretch the moment it was announced.

And the deal was even more confusing for the Orlando Magic than it would've been for other teams. Orlando already had Nikola Vucevic and Aaron Gordon. It acquired Serge Ibaka in the same summer it landed Biyombo.

The Magic could maybe try to explain that away by saying they wanted Gordon to be a 3, but that's not the way the game was trending.

Biyombo didn't fit, and that became clear pretty quickly. Over his two seasons in Orlando, Biyombo played just 20.2 minutes per game and the team's net rating cratered by 7.2 points when he was on the floor.

He was traded just two years after he signed this deal, and his role shrunk even further with the Charlotte Hornets.

3. Ian Mahinmi (4 Years, $64 Million from the Washington Wizards in 2016)

Ian Mahinmi had a bit more of a track record to point to than that of Biyombo's entering the 2016 offseason. 

In the 2015-16 regular season, the Indiana Pacers' net rating was 3.4 points better with Mahinmi on the floor. He averaged 9.3 points and 7.1 rebounds with a 60.3 true shooting percentage as a starting 5.

But that campaign came on the heels of six combined seasons with below-replacement-level production. And 2015-16 was his age-29 season. To commit nearly 17 percent of 2016-17's cap to a player heading past his prime with only one above-average season ended as you might expect.

Mahinmi is 826th (out of 864) in wins over replacement player over the last four seasons. And since that number is in the negatives, it actually could've been much worse if Mahinmi had been able to stay healthy.

During the course of this contract, the big man averaged 45 appearances per season. The 2017-18 campaign was the only one in which he surpassed 40 games. And he wasn't a regular starter until the final year (2019-20), when Washington was never a serious threat to make the postseason.

For a team that is in relatively dire financial straits due to the massive contracts for Bradley Beal and an injured John Wall, having Mahinmi on the books has all but eliminated cap flexibility.

2. Chandler Parsons (4 Years, $94 Million from the Memphis Grizzlies in 2016)

Chandler Parsons was a solid forward with some playmaking chops over the first five seasons of his career with the Houston Rockets and Dallas Mavericks.

He averaged 14.3 points, 3.0 assists and 1.7 threes during that half-decade. He posted a 1.7 box plus/minus (a "good starter" is around 2.0, according to Basketball Reference). His combination of size (6'9") and skill was intriguing.

But there was reason for concern ahead of the 2016 offseason. Parsons appeared in just 66 games in 2014-15, followed by 61 in 2015-16. A "mysterious" knee injury resulted in a 2015 surgery that the public knew little about for nearly half a year.

"In the world of NBA news, five months is an eternity for a secret to be held," Tim Cato wrote for SB Nation. "The fact that Parsons had a surgery wasn't kept under wraps -- he shared a post-surgery Instagram picture -- but the specifics were. In a press release, the Mavericks called it an 'arthroscopic surgery to address a cartilage injury in his right knee.'"

ESPN's Tim MacMahon had more details. According to his report, it was a "'minor hybrid' microfracture operation."

Two of the most notable recipients of a full-blown microfracture surgery prior to 2016 were Greg Oden and Amar'e Stoudemire. And it's fair to say that the results were less than stellar for both.

So in 2016, the Memphis Grizzlies pushed past those health concerns and offered a four-year deal, starting at $22.1 million, to a soon-to-be 28-year-old "good starter."

The deal quickly went sour for the Grizzlies. Parsons managed 34 appearances in the first season. He ground his way to 36 in Year 2, before falling back down to 25 in 2018-19. Before the final year on the contract, he was essentially salary-dumped to the rebuilding Hawks, who waived him before the 2019-20 season ended.

1. Timofey Mozgov (4 Years, $64 Million from the Los Angeles Lakers in 2016)

A small sampling of some of the reactions to Timofey Mozgov's four-year, $64 million deal from the Los Angeles Lakers in 2016 is instructive.

"In short, yes. It is absolutely insane," Macklin Stern wrote for Complex. "Know why? BECAUSE HE’S TIMOFEY FREAKIN’ MOZGOV!"

Sports Illustrated's Ben Golliver gave the move a generous "D+." He also pointed out that the Lakers' 2015-16 starter, Roy Hibbert, was 76th out of 76 centers in 2015-16 offensive real plus-minus, while Mozgov was 75th. So... upgrade.

The AP's Tim Reynolds tweeted, "I fully expect [Shaquille O'Neal] to come out of retirement if Mozgov is getting $16M a year."

We could play this game forever, but the point has probably been made. Hearing that Mozgov, who had just come off an age-29 campaign with averages of 6.3 points and 4.4 rebounds, snagged a deal this big was legitimately shocking.

Even most of those who had mentally prepared themselves for the sticker shock that would accompany the 2016 cap spike had to be taken aback by this contract.

And the reaction proved justified. Mozgov played in 54 games in his first season with the Lakers. Among the 282 players with at least 1,000 minutes in 2016-17, he was 276th in box plus/minus.

In the summer of 2017, he was traded alongside D'Angelo Russell to the Brooklyn Nets for Brook Lopez and a 2017 first-round pick the Lakers used to draft Kyle Kuzma.

He appeared in just 31 games for the Nets in 2017-18, and he hasn't been on an NBA floor for regular season action since. Brooklyn waived him ahead of the 2019-20 campaign.

Maybe the Lakers thought they were getting this guy.