Oh, what could have been with Tim Duncan

Five NBA championships to his credit, Tim Duncan announced his retirement after 19 seasons.David J. Phillip/Associated Press/File 2014

LAS VEGAS — It worked out great for the San Antonio Spurs, the 1997 NBA Draft lottery.

Not so much for the Boston Celtics.

The retirement of Tim Duncan after 19 seasons closes one of the more remarkable careers in league history. Five NBA championships. Nineteen playoff appearances. More than 26,000 points and more than 15,000 rebounds.

It was a storybook career, one that could have happened in Boston if those ping-pong balls had spun in the proper direction on May 18, 1997, when the Celtics had a 36 percent chance to land the top pick and Duncan was the prohibitive No. 1.

The story is well documented. San Antonio, which possessed the third-worst record in the league, won the lottery and drafted Duncan. The Celtics ended up with the third overall pick — as well as sixth — and selected Chauncey Billups and Ron Mercer, respectively.

Billups may have become an all-time great Celtic had Rick Pitino not given up on him after just 51 games. Mercer experienced back problems and was shipped out after two seasons.

It’s easy to play the “what if?” game and that’s been played in Boston for years and it’s pretty tired. Duncan is a sure Hall of Famer, a top-10 player of all time and is all San Antonio’s.

What is fascinating about those years is how much faith the Celtics placed on winning that lottery and how it essentially ruined the Pitino era and put the organization back several years. It seems Pitino really didn’t know what to do with Billups, a sophomore entry out of Colorado.

Tim Duncan posed in June 1997 after being selected No. 1 overall in the NBA Draft by the Spurs.Andy Hayt/Associated Press/File

The discarding of Billups to Toronto essentially ruined the 1997 draft for the Celtics. Pitino packaged Billups and Dee Brown and two other players and received former lottery pick Kenny Anderson, Popeye Jones, and Zan Tabak.

That’s quite a different return from Tim Duncan and the fact the Celtics received so little from that draft made the lottery luck appear even worse.

Franchise cornerstones can sometimes be difficult to determine. The Minnesota Timberwolves in 1995 could only have hoped high school entry Kevin Garnett would turn into an all-time great, and the same with the Los Angeles Lakers with Kobe Bryant a year later.

Duncan, however, was considered the surest thing to a franchise player since Shaquille O’Neal was taken by the Magic in 1992 and his presence would have catapulted the Celtics back to significance.

And what made that lottery loss even worse for Boston was that Duncan quietly turned into a superstar, embraced small-market San Antonio, and stayed there his entire career, only flirting with the Orlando Magic when his rookie contract expired.

The stability in San Antonio is staggering considering Duncan played for one coach — Gregg Popovich — for his entire career, and general manager R.C. Buford was able to maneuver the salary cap to retain the core of the team — Tony Parker and Manu Ginobili — for more than a decade.

The Celtics have had five coaches in that span and only began to approach stability when Danny Ainge hired Doc Rivers before the 2004-05 season after firing Jim O’Brien. The impact of the Celtics missing out on Duncan cannot be understated because of his consistency, impact, and longevity.

That should be celebrated because with Kevin Durant leaving Oklahoma City for Golden State and Dwyane Wade shocking South Beach by signing with the Chicago Bulls, the generation of players spending careers with one team perhaps ended with Kobe Bryant and Tim Duncan.

Paul Pierce didn’t finish his career in Boston. Garnett went back to Minnesota after a six-year stint in Boston. Staying power is rare in the NBA and Duncan exemplified dedication to an organization and that organization reciprocated.

The Celtics are seeking the type of culture that the Spurs have built. After Rivers left for the Clippers in 2013, the organization traded Pierce and Garnett to Brooklyn, hired 36-year-old Brad Stevens as coach, rebuilt quickly, and then re-signed Stevens to an extension when his contract was barely half-completed.

It’s easy to say Duncan would have had the same impact on the Celtics had he been drafted by Boston. But that’s no guarantee. But what the Celtics missed out on is perhaps the most reliable player since Bill Russell. And Pitino was so undeniably impatient with the team’s rebuild in the late 1990s that he followed up missing out on Duncan with the mistake of dealing Billups, drafting his former Kentucky player Mercer, and then eventually resigning when improvement was slow in coming.

That can’t all be blamed on the lottery balls. Not only did the Celtics miss out on Duncan, leaving an indelible mark on the organization, but it followed with making rash moves and poor trades. Duncan’s career should be celebrated and appreciated, but the sour taste remains for the Celtics faithful because it could have easily happened here.