He was the greatest champion in modern professional sports, and he was one of our own.

Bill Russell died Sunday. He was 88 years old.

He might have been born in Louisiana, died in suburban Seattle, where he had lived for 50 years, and won his 11 NBA titles in Boston.

But Russell was a son of the Bay, most specifically Oakland.

And while the legendary big man might no longer be with us, his legacy will live forever both in this region and everywhere the sport of basketball is played.

Oakland is rightfully called the City of Champions. Not only did all three of the city’s professional sports teams have brilliant runs of dominance, but it also has produced Hall of Famers such as Rickey Henderson, Frank Robinson, Joe Morgan, Jason Kidd and Gary Payton, and other champions including Dave Stewart, Marshawn Lynch, Paul Silas, Tony Lima, Vada Pinson and Andre Ward.

But Russell was the greatest champion of them all. He was — and will forever remain — the barometer for greatness in Oakland, the East Bay, the Bay and the sport of basketball.

Russell moved to Oakland when he was 8 years old. It was here where he started playing basketball — taking his prodigious athletic ability and translating it to the game that was in its infancy as a mainstream sport.

Any fan of the sport owes a great debt to whomever first put a basketball in Russell’s hands.

Russell’s basketball career started at Oakland’s McClymonds High School, where the late-blooming, lanky center with a loose grasp of the fundamentals barely resembled the player he would later become.

In fact, Russell planned on working in the Oakland shipyards after high school, hoping to save up enough money to go to college. Instead, a late and surprising scholarship offer to play basketball at the University of San Francisco paved a direct path.

That path, it turned out, was lined with titles.

Russell and a fellow son of the Bay, K.C. Jones, led USF to back-to-back NCAA national championships. The Dons won 60 consecutive games over that two-year span, becoming the first undefeated championship team in Division 1 men’s basketball history in the process.

It all worked around Russell — the 1955 and 1956 UPI College Player of the Year — who was the first player in NCAA history to average 20 points and 20 rebounds per game.

“We changed the game,” Russell told Sports Illustrated of his time at USF. “I think you can even say we developed a whole new philosophy of basketball. We attacked the offense and made it react to the defense.”

Russell took that new philosophy to the Boston Celtics in 1956.

His impact on the Celtics and the professional game was immediate. Behind Russell’s defensive mastery, the Celtics won the NBA title his rookie season. They’d win 10 more titles before Russell’s retirement after the 1969 season. The only years Russell and the Celtics didn’t win titles were 1958 and 1967.

Russell winning eleven titles was no accident. Russell becoming the first black coach in American professional sports was no accident. Russell coaching while still being a top player was no accident. And Russell being the greatest defensive player in the history of the NBA wasn’t certainly not an accident.

Russell had incredible athletic ability, but he studied the game, studied his opponents, and had a preternatural ability to understand the mentalities of both his teammates and those he was defending.

Some players’ success is defined by their stats — this many points per game and this many rebounds. But stats don’t tell the full story of Russell’s greatness.

No, the championships did.

And he was at the center of it all for his championship teams.

His defense, both inside the lane and out of it, ensured that USF Dons and Celtics had a championship-caliber team. It is estimated that Russell blocked eight shots per game during his NBA career though such stats are unofficial.

On offense, he could have scored more than he did. He averaged 15 points per game in his NBA career — on 13 shots per game.

Russell won five NBA MVP awards and has the NBA Finals MVP award named after him, but didn’t need gaudy numbers to tell the world just how good he was. The only goal was to win, and Russell did whatever his teams needed to bring about such results.

Basketball is a team sport, after all, and Russell was the ultimate team-first player. He is one of the eight players in the history of the sport to win an NCAA title, an NBA title and an Olympic gold medal (1956).

Russell lived a life of activism off the court. Some of his impact was created merely by his successes — he was an exemplary role model as a superstar player and later coach and executive. But he was also outspoken about the treatment of black players in Boston and across the country, even organizing a boycott of an exhibition game in the South when Russell and his black Celtics teammates were refused service in a restaurant before the contest.

In 2011, he was awarded the Presidential Medal of Freedom for both his incredible playing career and activism.

We all know that the Bay holds onto its own. But, unlike in so many regions, the adopted and locally born are treated with a similar, if not the same, reverence.

And when the Warriors won their fourth title behind the leadership and game-changing play of Steph Curry, I heard it asked if he — an adopted son of the Bay — is the region’s greatest basketball player. And in this basketball-mad region, that was to ask if he’s the greatest athlete in the Bay’s history.

As great as Curry is, that’s a silly question.

The truth is that everyone — the Oakland-reared, the adopted professional greats, and even the legends from San Francisco, San Jose, and everywhere in between — is only running for second place behind Russell.

He was the alpha of all alphas. He was the City of Champions’ greatest champion. And while he might be gone, we are forever lucky to call him one of our own.