Peter Borock, 23, is in his second year teaching history at Health Opportunities High School in the South Bronx. It could be his last.
With New York City schools planning for up to 8,500 layoffs, new teachers like Mr. Borock, and half a dozen others at his school, could be some of the ones most likely to be let go. That has led the schools chancellor, Joel I. Klein, into a high-stakes battle with the teachers' union to overturn seniority rules that have been in place for decades.
Facing the likelihood of the largest number of layoffs in more than a generation, Mr. Klein and his counterparts around the country say that the rules, which require that the most recently hired teachers be the first to lose their jobs, are anachronistic. In an era of accountability, they say, the rules will upend their efforts of the last few years to recruit new teachers, improve teacher performance and reward those who do best.