John McDonough, the interim Boston Public Schools superintendent, and Richard Stutman, president of the Boston Teachers Union, respond to this article here.

The Boston Public Schools system is now forecasting that about 200 of its existing tenured teachers will not end up with regular teaching positions once its new, open hiring process for the 2014-15 academic year is completed.

These surplus teachers are guaranteed a job at their current salaries, raising the specter of scores of teachers being paid not to teach. Ross Wilson, who heads the school system’s Office of Human Capital, said the cost of carrying those 200 teachers on the payroll should be minimal. He said many will fill in as long-term substitutes for other teachers out on leave. Those with poor evaluation scores will be assigned to assist other teachers in their classrooms.

Wilson stressed that none of the excess teachers will just sit around. “We won’t have a rubber room,” he said, a reference to the notorious offices in New York City where unwanted teachers with tenure used to spend their days playing board games, doing crossword puzzles, or napping.

John McDonough, the district’s interim superintendent, is exploiting a little-used provision in the teachers’ union contract to give the school system’s principals the same hiring freedom that heads of charter and turnaround schools enjoy.

The new hiring system replaces an old one that was almost universally scorned because existing teachers no principal wanted were often shoehorned into open positions. Principals responded by delaying hires or gaming the system to avoid hiring teachers they didn’t want. The result was a hiring process that dragged on and on, with nearly three-quarters of all hires taking place in August and September, when most good candidates had already taken positions at other school systems.

In an earlier interview with CommonWealth, McDonough acknowledged his new approach carried considerable risk. “There will be a significant cost up front in order to make this happen,” he said.

Wilson said the school system believes 75 percent of its hiring for the next school year will be finished by the end of April, and that the extra costs associated with surplus teachers will be minimal.

The hiring process began with about 800 teaching positions open, or about a fifth of the total teacher population system-wide. Wilson said principals have tentatively hired 548 teachers so far, filling nearly 70 percent of the open positions. He said he expects 75 percent to be filled by the end of the month.

Wilson said 522 Boston teachers were placed in the so-called excess pool, a place where educators whose old job has been eliminated wait for a new assignment. Of the 522, Wilson said 51 retired or resigned, 98 went out on long-term leave, and 83 were hired for one of the open teaching positions. Wilson estimates another 91 will be hired to fill open teaching positions, leaving about 200 owed a job under the teachers’ contract but unable to land one.

“At this point, we think it may be around 200 or maybe a little bit below that,” Wilson said.

The average salary of a Boston teacher is $88,000, suggesting the combined salary of those 200 teachers would be $17.6 million.

Wilson said many of those teachers will be asked to step in as long-term substitutes for teachers out on leave. He said the school system currently spends about $6 million a year hiring outside teachers to serve as long-term substitutes. Only those teachers who received a rating of proficient or better in their evaluations would serve as long-term substitutes, he said. 

The remaining teachers in the excess pool will be assigned to other open positions in the school system, Wilson said. Some teachers who received ratings of needs improvement or unsatisfactory in their evaluations will be assigned to assist other teachers in their classrooms, he said.