DOLAN HANDS KEYS TO MILLS & PERRY

It started to come crashing down three days before the start of the 2013-14 training camp.

The Knicks were coming off the Eastern Conference’s second seed and a 54-28 record. General manager Glen Grunwald had put the final touches on a roster everyone thought would compete for the Eastern Conference title. And suddenly, owner James Dolan struck, fired Grunwald and installed Steve Mills as president and general manager on the cusp of training camp.

Head coach Mike Woodson, a friend of Grunwald’s since their Indiana University days, was stunned and coached that way.

The explanation of Grunwald’s axing never made sense. Grunwald was too old-school. Mills was big on analytics, had better relations with agents and was a better recruiter as the Knicks sought to re-sign Carmelo Anthony that summer. It seemed as illogical as Dolan frowning upon ex-president Donnie Walsh because he spoke to the media too often.

The Knicks have been a wreckage since the Grunwald firing — writing the how-to book on ruining a franchise with mismanagement.

As it happened, the injury-riddled Knicks stumbled along into March with a losing record and Dolan panicked. His music-entrepreneur buddy Irving Azoff convinced him Phil Jackson and his magic triangle would be the panacea. Jackson was hired March 19, 2014 — Mills demoted to general manager after five months on the job.

Three years and three months later, after the worst waste of $60 million in professional sports, Dolan has hit the rewind button.

Jackson has been shipped back to Montana to size up lovely views from his lake house.

Mills is back in the presidency role, and this time he has an experienced basketball personnel man by his side who wouldn’t know the triangle if it hit him upside the head. Dolan stated in a press release a “culture change” will begin to re-establish “a work ethic” and “pride” — perhaps a shot at Jackson.

You probably had never heard of Scott Perry, who received a five-year deal to become the Knicks’ general manager. Perry has been in the front office of four franchises, including the Pistons for many years, winning a title there in 2004. The worst thing one executive said about Perry is he “micromanages” too much. But Mills will be on better footing in his second chance to run the Knicks with the well-respected Perry as his right-hand man.

With Jackson silently presiding over, that 2013-14 Knicks club