Go-to source Jack Jennings, who has led the Center on Education Policy since he founded it 17 years ago, is retiring Jan. 31. His partner-in-crime, Diane Stark Rentner, also known as the director of national programs for the center, will become the interim director.

Under Jennings, the center has analyzed the implementation of No Child Left Behind, the turnaround of the country’s low-performing schools, and the status of state high school exit exams. Heck, If it weren’t for Jennings & Crew, we might not know that Education Secretary Arne Duncan’s claim that 82 percent of schools this year would “fail” under NCLB was way off base.

A former longtime aide to Democrats on the House education committee, Jennings is a legend on Capitol Hill. Lawmakers in both parties singled him out, by name, during hearings to thank him for his expertise. And nearly every version of the Elementary and Secondary Act has his fingerprints on it. He has a Wikipedia-esque knowledge of every corner of the law, but he can explain it in simple terms even a reporter can understand.

As he retires, he’s leaving behind some parting thoughts—a post-game analysis of sorts of the last half-century of education reform, and recommendations going forward. He writes: “We can talk for another 50 years about making the schools better, and succeed for some.We can adopt piecemeal approaches that have some effect. But if we want broad, major improvement for our nation’s schools, we have to act boldly, not just talk or try partial fixes.” It’s worth a read.