On Saturday, in what he says will be his final fight, Mayweather will pit his skills against Conor McGregor, the first Mixed Martial Arts (MMA) fighter to hold two world titles simultaneously in the Ultimate Fighting Championship. The Mayweather vs. McGregor fight, in Las Vegas, will be a “crossover” contest held under the Marquess of Queensberry Rules –traditional boxing regulations that play to Mayweather’s strengths.

A native of Grand Rapids, Mich., Mayweather is an undefeated 12-time world boxing champion in five different weight classes. With a record of 49 bouts with no losses as a professional boxer, Mayweather is widely recognized as one of the greatest fighters to ever lace a pair of boxing gloves. Last year, ESPN ranked him the number one boxer, pound for pound, of the last quarter century. He has also been a stunningly effective income generator: In 2015, by one estimate, he earned about $66,000 per second in the ring.

If he wins, Mayweather will take the title of the longest unbeaten record in boxing history – a distinction he jointly holds with the late heavyweight champion, Rocky Marciano. Mayweather will also regain the title as the highest paid athlete in sport – racking up an estimated $400 million for, at most, 36 minutes in the ring, to bring his career earnings from boxing to about $1 billion, according to Forbes. McGregor is expected to collect $127 million. (A confidentiality clause is in place in both boxers’ contracts, which prevents them revealing the exact purse split.)

Post-boxing life, Mayweather says, will involve promoting other fighters, building his fashion brand, and supporting important non-profit work. In an interview with Fortune in the run-up to his historic fight, Mayweather described how he evolved from athlete to brand, and the lessons he learned along the way.

1. Know your business, and own it.

Mayweather originally fought as a client of Top Rank, a Las Vegas-based boxing promotion company which, over the past 44 years, has represented some of the sport’s all-time greats – from Muhammad Ali and his arch rivals, to Mayweather and his former nemesis, Manny Pacquiao.

After spending a few years in the Top Rank stable, Mayweather says, he began studying the contractual side of the sport. “I came to understand what my boxing contract meant and all the ways I could have more control over my value and my earnings,” explains Mayweather.

In 2006, Mayweather parted ways with Top Rank by invoking a $750,000 buy-out clause in his contract. The following year, he formed his own company, Mayweather Promotions. Mayweather expounds on the benefits: “When I fight, I get a percentage of everything that goes into making the event a success – site fee, pay-per-view sales, international sales, merchandise, concessions and so on.”

Mayweather advises sporting prospects and entrepreneurs to “educate [themselves] and understand what’s on the table in terms of the overall success of [their] brand or the event [they’re] participating in.”

2. Drive a hard bargain.

Mayweather has a reputation for being intimately involved in every aspect of the fight game – including brokering his record-breaking fight fees and marketing deals.

In 2013, his team negotiated what was reported to be the richest individual athlete deal in sports– a six-fight, 30-month deal with Showtime/CBS that secured him a guaranteed minimum of $200 million. Two years later, Mayweather personally initiated negotiations for the “Fight of the Century” against Pacquiao, which is currently the richest fight in the annals of boxing. Then, in 2016, Mayweather brought McGregor to the negotiating table to broker this weekend’s fight, which is expected to become the highest-grossing event in the history of boxing or MMA.

Mayweather often delegates the nitty-gritty of negotiations to his team, including Leonard Ellerbe, CEO of Mayweather Promotions, and Al Haymon, Mayweather’s long-time adviser.

But he himself offers three negotiation tips. “Firstly, know your worth and the value you bring to the table. Secondly, be prepared to defend yourself at the negotiating table and walk away if you need to.” Third, be confident: “When it comes to negotiation, confidence gets added to the equation.”

3. Build the right team—and recognize them publicly.

Mayweather understands that, as gifted as he is in the boxing ring, building a brand can’t be done alone. Over the years, he has openly commended his team—including Ellerbe and Haymon—for their role in his success. He also singles out Kelly Swanson, his publicist of the last 12 years. Swanson doesn’t try to manufacture his image or censor his speech as some publicists might, says Mayweather: “She’s always encouraged me to be my own person, and that’s helped me get my brand message out.”

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Despite his induction into the International Boxing Hall of Fame being a virtual certainty, Mayweather says he wants to be better known for his business acumen than his boxing accolades.

In addition to wearing his fighter-promoter hats, Mayweather is the CEO of The Money Team (TMT). What was originally a moniker for his closest associates became a lifestyle brand that consists of clothing lines for men, women and children. “When I changed my [nickname] from ‘Pretty Boy’ to ‘Money’ and created the TMT brand, it gave me the path to build my identity outside the ring,” reveals Mayweather.

The TMT brand, which was launched in 2012, has partnerships with retailers including LIDS and Hat Club. TMT products have been rolled out to 18 retail outlets in five countries. (In the build-up to the McGregor fight, Mayweather’s team has also set-up “The Money Fight” pop-up shops in Los Angeles and Las Vegas.)

Mayweather will also leverage his fame to help promote social causes he believes in. He has become an advocate of the Moblze Foundation – a new non-profit organization aimed at rebuilding U.S. inner cities through entrepreneurship and mentorship programs that will train high-skilled workers. (Those aims mirror some of the goals of Mayweather’s not-for-profit organization, The Floyd Mayweather Jr. Foundation.)

For Mayweather, it’s just as important to invest in grassroots entrepreneurship as it is to make smart private investments. “With the new administration, it’s important that we don’t forget our inner cities,” he cautions. “Whatever economic and social changes are implemented, we have to make sure these changes trickle down to these communities and people aren’t left behind.”

If the McGregor fight is indeed Mayweather’s swan song (he has officially “retired” at least three times before), his vision of life after boxing still largely centers on the sport. He’ll continue to run Mayweather Promotions, which has about 20 fighters in its ranks.

And unlike many boxing champions before him, Mayweather appears to be set to depart from prize fighting with his health and finances in good shape—which will perhaps be his biggest victory.