One of the most exciting times of years for NBA fans is the start of free agency. For a few minutes, until the announcements start pouring in, every fan can believe their team is about to make a move that puts them into contention for the playoffs or even the Finals.

Once players start making their decisions, though, the number of disappointed fans grow. Kawhi Leonard will break hearts somewhere. It is a 100 percent certainty that some teams will strike out.

Some will reach for a start they can't obtain, and some will fail to retain the stars they already have. Some won't take the step forward they wanted to take. Some will take a step back.

These are the franchises in the most danger of that happening.

New York Knicks

New York Knicks fans should prepare themselves for good news and bad news. And then maybe a little more bad news. 

The good news is that the Knicks have a lot of cap space. According to Keith Smith of Yahoo Sports, they have $70.5 million in estimated room. They could sign two max players and still have money left over. 

The bad news is that players must agree to play for that money, and that's where the trouble begins.

The Knicks' Kevin Durant dreams are not looking good. According to his former Oklahoma City Thunder teammate, Kendrick Perkins, the Brooklyn Nets are "the frontrunner," as relayed by Brian Lewis of the New York Post.

On CNBC (h/t Spike Eskin), Andre Iguodala warned: "Nobody's going to the Knicks, sorry."

And the news from the New York front office might be the most damning of all. Asked how fans should feel about free agency, team president Steve Mills told the New York Daily News, "I think we're asking them to continue to be patient." 

That doesn't sound like someone who has high hopes of bringing in a couple of superstars. It might be better for the Knicks not to go for the shortcut, but to instead use the cap space to acquire draft picks from teams looking to move contracts. 

But few fans have had more patience with less reward than the Knickerbockers faithful, and another bad offseason—a real possibility in 2019—wouldn't help. 

Sacramento Kings

The Kangz may finally have been deposed, as the Kings are climbing back on the throne in Sacramento.

Led by their backcourt of Buddy Hield and De'Aaron Fox, they are looking to move back into the postseason for the first time since 2005-06. As a result, they're walking on a wall right now, and they could topple off in two different ways that end badly. 

They have two notable free agents: Harrison Barnes and Willie Cauley-Stein. Barnes opted out of his contract, but there is still hope he will remain there, according to James Ham of NBC Sports: "At 27 years old, Barnes has plenty of basketball in his future, and the Kings would like him to remain a part of that. According to multiple sources, the Kings are confident they can lock up their starting small forward to a long-term deal."

Jason Anderson of the Sacramento Bee reported a return does not look as likely for Cauley-Stein, as Roc Nation Sports representative Roger Montgomery has told the team his client wants out:  

"We've kind of hoped that things would change over the years and Willie would get a chance to expand his game, get a chance to get some consistency there in terms of the roster turnover and the coaching turnover and the things that have not been steady there. That being said, I'm hopeful they will not even give Willie his qualifying offer so Willie can be an unrestricted free agent."

The Kings just might cooperate. Letting Cauley-Stein go could open up enough cap space to negotiate an agreement with Barnes and have enough left for a max deal. They could use that to chase after Nikola Vucevic or Al Horford.

Either of those options could work well.

However, if things go badly, they could lose Cauley-Stein and be left flailing for a new starting center. That could potentially lead to an overpay of someone like Bobby Portis or—dare I say it?—DeMarcus Cousins, tying up cap space and derailing the long-awaited return to the postseason. 

Indiana Pacers

The Indiana Pacers haven't just survived since trading away their former superstar, Paul George. They've thrived.

Victor Oladipo has become a star. Myles Turner was fifth in voting for Defensive Player of the Year. Domantas Sabonis was sixth for Most Improved Player. Bojan Bogdanovic became a borderline star after Oladipo went down with a knee injury last season, averaging 21.2 points over his last 31 games.

They finished fifth in the Eastern Conference despite a plethora of injuries. 

Now they need a point guard to guide them to the next level, and they're hoping D'Angelo Russell will be that guy. According to Ian Begley of SNY, "Members of the Pacers organization are high on Russell." 

That's as it should be. Russell is an all-around player who would complement Oladipo splendidly. Both men can play on or off the ball, and both are willing passers. 

Here's the catch: Russell is on a lot of teams' wish lists. 

The Phoenix Suns want him. The Minnesota Timberwolves do, too. Don't rule out the Los Angeles Lakers. And there's always a chance he stays with the Nets if the whole Kyrie Irving thing doesn't work out. 

But the Suns haven't made the strongest personnel decisions in recent years. Minnesota is still Minnesota. The bridges in L.A. are still smoldering. And Brooklyn looks like it is going to get Kyrie. All of that can give Pacers fans a lot of hope. 

However, Indiana is still saddled with its status as a small-market team, and that might be hard for it to overcome. It may come down to how much cap space the Lakers can generate and whether Russell can get over their previous breakup.   

Boston Celtics

Boston could endure a lot of trouble this summer, as two of the Celtics' biggest stars look to be on their way out.

According to Brian Lewis of the New York Post, "Multiple sources throughout the NBA believe Irving is leaning toward signing a four-year, $141 million deal with Brooklyn once free agency starts Sunday."

At this point, it would be a shock if that doesn't happen. More surprising is that Al Horford also seems to be on his way out.

Steve Bulpett of the Boston Herald first broke the news, tweeting: "Major change in the Al Horford situation:
Per source close to Horford, his side is no longer discussing a new 3-year deal to stay with the Celtics. He is expected to sign a 4-year free agent contract elsewhere..."

After trading Aron Baynes to the Phoenix Suns on draft night, the Celtics opened up $23 million in cap space should both Irving and Horford leave. But there's no way they can make up for that kind of talent loss with $23 million. 

Wojnarowski puts them as the front-runners to get Kemba Walker. But even if they land him, they are still net losers in free agency. 

After making it to the Eastern Conference Finals in 2017 and 2018, the Celtics looked like they were primed to take over the East once LeBron James left for the Los Angeles Lakers. But they didn't get back there this year, and they're set to lose two of their biggest acquisitions.

Now, the future is not nearly as certain. 

Toronto Raptors

The higher up you go, the further you have to fall. You don't get any higher up than the Toronto Raptors right now. 

In sending DeMar DeRozan, Jakob Poeltl and a 2019 first-round draft pick to the San Antonio Spurs for Leonard and Danny Green, the Raptors gambled that they could keep Leonard if they won it all. Now it's time to see if that gamble paid off. 

Leonard is now the defending Finals MVP and a free agent. He had one of the most historic postseasons on record. His 732 points trail only Michael Jordan (1991-92) and LeBron James (2017-18) for a single playoff run. 

But he has yet to confirm he plans to stay in Toronto. 

Adrian Wojnarowski and Zach Lowe of ESPN discussed the situation on Woj & Lowe 2019 NBA Free Agency Special (h/t Silver Screen & Roll's Anthony Irwin): 

"Lowe: It seems like it's a two-team race. Is that fair at this point?

"Woj: Yeah. Toronto, the Clippers, and listen, I think they've kept their eye on the Lakers, and what that's going to look like. The Lakers, financially, what number are they going to get to in free agency in terms of cap space? Is Anthony Davis going to give up that $4 million trade bonus? He still has time to do that before this deal goes through.

"But this has been a Raptors/Clippers race. And you gotta give the Raptors and Masai Ujiri, that organization, all the credit in the world, because when they traded for him, he had no intention of ever staying in Toronto, and now it is a serious consideration.

"I think he has really given them every opportunity to sell him, and two things that have worked in Toronto: They sold him on health, they proved they could keep him healthy, and they sold him on winning. And those are priorities for Kawhi Leonard. He has shown he is all about winning."

If he agrees to stay, that would be the most rom-com moment between player and team in recent memory. However, it could make it even worse for Raptors fans who were expecting him to leave but then started getting their hopes up about him staying. 

Do the Raptors make the original trade again if they know Leonard leaves after one title-winning season? Absolutely. Does that make the landing any easier if they fall from the peak of the NBA world? No. 

No team has as much to lose as the Raptors because no other team is defending the title.