Lowe: The juicy subplots that could tilt this Mavericks-Celtics NBA Finals -- and who should win

David Butler II-USA TODAY Sports

THE FUN OF sports is that a matchup like these NBA Finals between the Boston Celtics and Dallas Mavericks can feel both inevitable and surprising.

We came within one series of getting this Finals two years ago. A Boston return was long assumed, even after it melted under a maelstrom of Miami Heat 3s in last season's Eastern Conference finals. But flash back to the spring of 2021, and everything seemed so precarious for a franchise that envisioned a near-decade run of contention around Jayson Tatum and Jaylen Brown.

Those 2020-21 Celtics finished .500 and whimpered out of the first round, overwhelmed by the East's new superteam -- the Brooklyn Nets of James Harden, Kevin Durant and Kyrie Irving. Many within the Celtics still whisper about that series -- the sense of helplessness, the fear the East had passed them by.

The roster around Brown and Tatum was a mess. Kemba Walker's body betrayed him. Young players were not ready. Free agent signings and trades busted. Illnesses and injuries, including Brown's season-ending wrist injury, did the rest.

In a two-year whir, Boston reconstructed everything around its two stars -- swapping Walker for Al Horford, then striking deals for Derrick White, Jrue Holiday and Kristaps Porzingis. The Celtics rectified mistakes and were aggressive trading assets for talent.

The Mavs went through an even more accelerated remake after their 2022 Western Conference finals run. The only holdovers are Doncic, Maxi Kleber, Josh Green and Dwight Powell. The Mavs assumed more future risk than Boston in undoing past errors -- including the seismic blunder of letting Jalen Brunson escape -- but no one is much worried about that now after watching the Mavs confound three of the West's top-four seeds.

Zoom further out and you gain even more appreciation for all the variables that could have torpedoed this matchup -- of how that history underlines the massive stakes now.

Boston had so many chances to speed up the Tatum/Brown era by trading one of them -- or the picks it ended up using to select both -- for restless superstars: Paul George, Jimmy Butler, Durant, Kawhi Leonard, Anthony Davis.

The Celtics used their final Nets pick to acquire Kyrie Irving in 2017, pairing him with Gordon Hayward as splashy offseason acquisitions. Internally, Boston envisioned Irving as the lure to convince Davis to push his way to Boston -- a trade that almost surely would have cost the Celtics either Tatum or Brown.

That plan teetered five minutes into Hayward's Celtics debut, when he shattered his leg. It was a basketball tragedy; Hayward was never the same. It is also a massive sliding doors moment. If Hayward stays healthy, do Brown and Tatum develop as fast? Does Irving grow unhappy leading the young Celtics? If not, does Boston actually have a chance at Davis?