A closer look at data from individual high schools reveals a trend that might seem contradictory at first glance: Schools whose graduation rates are rising are simultaneously losing a significant number of students to charter schools and schools in other parts of town.

Lincoln High has come to represent everything that troubles large urban high schools: continuous staff turnover, lagging test scores, eruptions of violence and students segregated by race, poverty and language. This year, Lincoln will get a new school board trustee and a new principal. Both leaders will face the improbable task of reversing decades of low performance and low expectations for students at San Diego Unified’s most embattled campus.

Next year John Ross, who was appointed to lead Lincoln in 2014, will move to the district’s Placement and Appeal Department, where he’ll work with students who’ve been incarcerated or are facing expulsion. Ross becomes the third principal to leave Lincoln since 2007, when the school reopened with a $129 million campus.