Projecting the NBA offseason is notoriously difficult to do, primarily because so much of what a team is able to accomplish depends on the internal motivations of the individual players involved. We know the maximum amount of money that a player such as LeBron James can sign for, and we know that he will get it if he asks for it. But it is also well within his power to accept less money to help his general manager build a better roster around him. And given the NBA's salary-cap rules, as little as a couple of million dollars can be the difference between being able to make a move and not make a move.

That being said, the closer you look at the Sixers' options for making a big splash in this offseason's free agency, the more you suspect that their best 2018-19 roster would start with a trade for Kawhi Leonard rather than a signing of James or Paul George.

Here's why:

1) Leonard would likely give the Sixers more payroll flexibility to build around him, at least over the first three years. 

This is assuming that the Sixers agree to a max contract extension that begins in 2019-20. In such a scenario, the Sixers would be paying Leonard $20.1 million in 2018-19 (the last year of his current deal) and $32.4 million in 2019-20 (Year 1 of his extension). That's a savings of $10.2 million over a max deal for Paul George and $15.25 million over a max deal for LeBron in 2018-19. In 2019-20, Leonard would cost about a half million more than George and about $5 million less than LeBron.

Below, you'll find the projected annual values of contracts for Leonard if he signs after a trade with the Sixers and Leonard if he re-signs with the Spurs, plus James' max breakdown and George's max breakdown. Take a look, and then meet me on the other side for some explanations.

2) If the Sixers acquired Leonard, they'd still have a chance to add more talent. 

Bryan Colangelo estimated their available cap space at around $25 million, but that does not take into account several roster moves that could easily add some critical millions to that total. In the table below, you'll find the Sixers' current payroll situation, which includes a couple of easy moves that would free up money.

The first is waiving Jerryd Bayless and using the CBA's "stretch provision" to pay out the $8.5 million remaining on his salary over three seasons instead of one, which would free up about $5.7 million. The second move is declining Richaun Holmes' option, which would free up another $1.6 million.

You'll also find three different "cap holds" included in the Sixers' salary total: one for the projected No. 10 pick, one for the No. 26 pick, and one for draft-and-stasher Anzejs Pasecniks. The CBA requires a team to count these prospective rookie contracts against its cap total until it reaches an agreement on a contract or an agreement that it will not sign the pick in question for the current year.

The Sixers would have to clear a little more space should LeBron require the max, but that wouldn't be too difficult. Inefficient, perhaps. But it can be done. They could renounce the right to sign Pasecniks to a contract this season, trade the No. 26 pick or use it on a stash, and either part ways with Justin Anderson or trade Bayless to a team that will agree to take on his salary in addition to a draft pick or player (or both).

Acquiring Leonard would still leave the Sixers with about $11.5 million in cap space even before they got creative with their roster.

3) Any trade for Leonard would almost certainly clear even more money and increase that $11.5 million cap room.

I'm skeptical as to how much trade value Markelle Fultz has right now. You have to keep in mind that the Lakers could offer the Spurs a package headlined by second-year standout Brandon Ingram. Ingram almost certainly has more value than Fultz.

Assuming the Spurs are not enamored with Fultz, the ideal/fair move might be Fultz and the projected No. 10 overall pick, perhaps with a future draft pick. I'm still not sure they can beat the Lakers in a bidding war unless they include Dario Saric. But for the purposes of this discussion, Saric is less relevant, because of his low salary. Fultz and the No. 10 pick, on the other hand, would clear an additional $11.4 million in cap space, leaving their total room at $22.9 million. That's enough to add at least one other quality piece via free agency. Say, the Nuggets' Will Barton. Or a re-up with JJ Redick.

It's also within striking distance of the room they'd need to clear to add another max guy. Say, George. Trade Robert Covington and Anderson and they'd be there, with $35.9 million to spend. They could also trade Timothe Luwawu-Cabarrot and pay someone to take Bayless' salary.

Dream along with me for a moment and imagine this lineup:

This would obviously require the Sixers to be comfortable going into luxury-tax territory starting in 2021-22. This is a roster that would get really expensive really fast.

Still, even if they were to acquire Leonard and not add a second max contract, they'd have room to fill out their roster and make it more well-rounded.

4) That being said …

The Lakers are going to be tough to beat in a bidding war for Leonard and George. There's an outside chance that L.A. could even find a way to add George, Leonard, and LeBron. With Ingram and fellow young up-and-comers Kyle Kuzma and Josh Hart, L.A. has a lot of firepower it can use to beat the Spurs' next-best offer for Leonard. And, keep in mind, Leonard and the Spurs would actually have to agree to divorce, and that would mean Leonard's leaving $30 million-plus guaranteed, since the Spurs can offer him a SuperMax deal.

A trade for Leonard makes sense in a lot of ways. But it's one of only many directions in which this offseason could turn.