Boxing is a sport without seasons, making it hard to identify strict beginnings and endings to its eras. It takes time to identify who the real players in a memorable time period will be and for older names to fade. A constant fluidity only looks concrete from a distance.

Even without a firm start date, Saturday’s Showtime (9 PM EST) main event feels like a destination the Jr. middleweight division has been building toward in the most organic way possible.

This main event was built through a series of fights and a minimum of social media posturing.

One of the highlights of the sport over the last five or six years has been an unofficial round robin at 154 lbs. When lineal, Ring, WBC, WBA, and IBF champion Jermell Charlo (34-1, 18 KO) and WBO titlist Brian Castano (17-0-1, 12 KO) lock horns, with the winner also to be recognized as the king of the class by TBRB, it will be the culmination of an era.

We don’t get those very often and culmination isn’t meant the same as an ending. The winner could go on to defend several times. The fight might be good enough to force a rematch. Where the story goes from here will be determined.

The road to this fight is enough to make the journey worth appreciating.

Showtime has had the fortune of airing memorable culminations before. In 2008, the three-belt Jr. bantamweight unification bout between Vic Darchinyan and Cristitan Mijares was an excellent match on paper and provided Darchinyan arguably his career best win. In a vacuum, that was more than enough for a good fight night.

The fight didn’t happen in a vacuum. Darchinyan-Mijares emerged from several years of quality action in the division before whittling to those two. Names only hardcore fans might recall like Masamori Tokuyama, Katsushige Kawashima, Martin Castillo, Nobuo Nashiro, and Alexander Munoz created a round robin not unlike what we’re seeing at Jr. middleweight. Throw Jorge Arce in the mix for some relative star power, along with pieces of the careers of Nonito Donaire and Fernando Montiel, and by the time the belts came together it just felt like a making whole.

We didn’t see every combination of the key players but that nearly never happens in any division or era. We just saw enough of them to know everyone got a bite at the apple.

That’s what this weekend feels like. 

The Jr. middleweight culmination between Charlo and Castano is the final piece to make this era whole.

If there is a start point to this era, it comes between Floyd Mayweather’s abdication of the lineal throne in 2015 and Saul Alvarez’s final exit from the division in 2016. The new players were emerging all along and some of Mayweather and Alvarez’s peers in the division carried over, namely Erislandy Lara and Austin Trout.

Add those last two names and the names battling this weekend to the following prominent contenders and titlists since 2016: Jermall Charlo, Erislandy Lara, Jarrett Hurd, Julian Williams, Jeison Rosario, Erickson Lubin, Michel Soro, Tony Harrison, and Patrick Teixeira. 

Jermall’s wins over Trout and Williams can read almost as a prologue to what would follow, given his rise to middleweight and their overlap with Alvarez’s last Jr. middleweight win against Liam Smith.

Since Charlo-Williams in 2016, these names have mixed and matched a number of ways. Hurd defeated Harrison, Trout, and Lara before falling to Williams. Jermell Charlo defeated Trout, Lubin, and got the better of split fights with Harrison with a rematch knockout. Williams lost to Rosario and Charlo beat him too his last time out, unifying three belts for his trouble. 

While all this was going on, Castano flew largely off the US radar, handing Soro his lone loss since 2012 before turning some heads with a narrow draw outing against Lara. Castano’s win over Teixeira was dominant and combined with his other significant outings made him more than a guy with another belt to pick up.

Both Charlo and Castano arrive here with real experience, real achievement, and a real chance to plant their flag as the last man standing. The winner will truly have earned the right to call themself the champion of the world.   

Champion.

Singular.

As much as the fighters have earned their way here, the series of events that led to this Saturday, this era at Jr. middleweight, has earned nothing less.

May the best man win.

Cliff’s Notes…

Saul Alvarez dangling Gennady Golovkin as an option aside from Caleb Plant just means he’s choosing between two interesting fights. Either will do and both are likely in some order...Did Fox really air a press conference between Errol Spence and Manny Pacquiao? It’s wild to see boxing get treated like a real sport on big outlets...Black Widow was good. It wasn’t Marvel’s best though it flirted with Winter Soldier level quality in the first half. They quipped and styled through some of the darker subject matter the youth friendly brand has tackled to date to take their foot off the gas...Terence Crawford not fighting anyone from the PBC has been a waste of several years. Not fighting at all so far this year is just wasted time in general.        

Cliff Rold is the Managing Editor of BoxingScene, a founding member of the Transnational Boxing Rankings Board, a member of the International Boxing Research Organization, and a member of the Boxing Writers Association of America.