Back in the days of Mayor Bloomberg and Joel Klein, the policy of the city was to close big high schools that had varied programs (e.g., music, the arts, advanced classes in math and science) and replace them with small schools. Almost every large high school in the city was closed. One of them was DeWitt Clinton, which had become a dumping ground for the small schools that did not want students with low test scores, English learners, and students with disabilities. In effect, the school–once known for its excellence–was turned into a graveyard.

Klein and his acolytes touted the New York City Miracle, built on testing, testing, testing, and small schools.

A piece of the architecture fell apart recently at DeWitt Clinton, when teachers leaked that students who never attended class were getting good grades and graduating, based on credit recovery by computer (at home).

This high school is a hooky player’s dream.

At DeWitt Clinton HS in the Bronx, kids who have cut class all semester can still snag a 65 passing grade — and course credit — if they complete a quickie “mastery packet.”

Insisting that students can pass “regardless of absence,” Principal Pierre Orbe has ordered English, science, social studies and math teachers to give “make up” work to hundreds of kids who didn’t show up or failed the courses, whistleblowers said.

“This is crazy!” a teacher told The Post. “A student can pass without going to class!”

The 1,200-student Clinton HS is one of 78 struggling schools in Mayor deBlasio’s “Renewal” program. Last year, 50 percent of seniors graduated, but only 28 percent of the grads had test scores high enough to enroll at CUNY without remedial help.

The DOE’s academic-policy guide says students “may not be denied credit based on lack of seat time alone.” Passing must be based “primarily on how well students master the subject matter.”

Orbe has taken the policy to a absurd extreme, teachers charge.

Leonie Haimson of Class Size Matters says that DeWitt Clinton, which is part of Mayor de Blasio’s “Renewal Schools” initiative, has very large classes, some as large as 39. That’s one remedy that the mayor ignored.

By the way, if you want to meet Leonie (and me), we will be at the annual dinner of Class Size Matters tomorrow night in New York City. It is not too late to get a ticket.