The resignation of Celtic head coach Jim O’Brien this week is a revelation of innumerable points regarding this once great franchise. None of those points is positive at the moment.

O’Brien left because he could not work with new director of basketball operations and former Celtic player, Danny Ainge. Ainge said the parting was due to “philosophical differences.”

Once upon a time Red Auerbach led the Celtics as coach and GM, and the owners and he were friends in a “here’s a cigar, let’s have a drink and talk” kind of friendship. The Celtics lived off that image and modus operandi for years.

Those days are long gone. Said Auerbach on Wednesday, “It came as a shock, but I could see it happening because they had two different philosophies.”

The latest Celtic owners, Wyc Grousbeck and Steve Pagliuca, bought the Celtics on the downside, hoping the name would withstand the losses until the phoenix could rise from the FleetCenter.

Ainge was brought in because he is a name affiliated with winning Celtic years. Ainge is ambitious and impetuous. When he arrived he wanted to quickly assert his plan and did so by trading players O’Brien believed were essential to success.

Ainge was running the show with little input from the now former coach. O’Brien saw a future of testiness and conflict, deciding the situation was unworkable enough to leave behind two more years on his contract and some $6 million.

Said O’Brien on Wednesday, “At the end of the day, I just felt if he’s (Ainge) going to grow this exactly the way he wants, he needed followers that believed in how he was going to grow it.”

Once O’Brien walked out of Ainge’s office, assistant coach and O’Brien’s friend Dick Harter was fired, just to make it clear this is about Ainge, not O’Brien.

There may be an irony here. Ainge is well aware of the Old Celtic way. He knows Auerbach ran the ranch with an iron hand and ownership fully behind him. Winning didn’t hurt.

Ainge is following the adage that if you are going to fail, do it on your own terms. The Celtics are his now, as they were Auerbach’s during all those championship seasons.

All the decisions emanate from Ainge’s office and he will attempt to build the team in the image HE has of a winner with the players and coaches HE deems necessary to reach the promised land.

There is obviously nothing wrong with that, but this is one tough way to start.

The players respected O’Brien. When he took over for self-promoting, egocentric Rick Pitino three years ago, O’Brien was an unknown. He established himself as a thoroughly solid strategic coach, placing the players first and winning through quiet leadership.

Ainge has chosen another route. He says he will not go back behind the bench, though he has been there before. Rather, he will try to establish an organization so in tune with his definition of success that it will necessarily travel his path on the court even if he’s upstairs.

In an NBA that is losing its luster to crudeness on and off the court by its players, Ainge has a unique opportunity, even if it is dangling from a precipice to start.

If he can build a winner and return both W’s and pride to the Celtics, and he could establish an example for the NBA.

If he meets resistance from reluctant players who view the league as an endless money pit to which they only have to show up to be paid, he will soon follow O’Brien onto Causeway Street.

Unfortunately, in today’s NBA, he has precious little time to make his mark.

Old Town native Gary Thorne is an ESPN and NBC sportscaster.