Elliott Witney, a brilliant reading teacher, was one of the six people who launched KIPP, now the nation’s largest charter school network, in a Chicago hotel conference room 14 years ago. He eventually became principal of KIPP’s flagship school in Houston. So, why has this hero of the charter movement taken an administrator job in a traditional Houston area district full of bureaucratic annoyances charters were created to eliminate?

That is one of the many surprising questions asked and answered in Richard Whitmire’s intriguing new book, “On the Rocketship: How Top Charter Schools Are Pushing the Envelope.” It is the best account yet of what is happening with charters. Both those who hate the independent public schools and those who love them should read it.

Whitmire does not hide charter struggles and mistakes. The Rocketship charter network at the center of his story soars, then sputters, then twists and turns. Whitmire is as sympathetic to the parents and educators opposed to Rocketship as he is to the entrepreneurs and educators who created the network.

Whitmire makes no secret of his support for charters, even while explaining wild ideas like Rocketship founder John Danner’s belief that he can achieve Fibonacci growth — a reference to a 13th-century Italian mathematician — and have a million students by 2030. By exposing charter missteps, Whitmire is a more convincing chronicler of this dynamic part of today’s schools than any of the anti-charter bloggers.

At one point, Preston Smith, executive director of Rocketship schools in San Jose, was told by Danner to institute what most experienced educators would consider an insane plan: Knock down walls so elementary school classes could expand to 120 students each. That idea bombed in the 1970s, but Danner, a confident multimillionaire, insisted on it. Only when Smith’s staff revolted was the plan shelved. “Three-quarters of my executive team was ready to go out the door,” Smith told Whitmire.

It got worse. Media reports had suggested that Rocketship was the best new thing in charters. Its devotees said it used computers so efficiently that student achievement would soar without extra fundraising to augment government funds, as organizations like KIPP had to do. But its first venture outside Silicon Valley faltered. Resistance in union-strong Milwaukee was so vehement that Rocketship’s growth projections had to be revised.

Yet Whitmire still sees Rocketship on an upward track. He argues that charter growth is inevitable. Once parents have a chance to choose something other than their struggling local urban schools, they will do so, he says. If enough charters outperform local schools, parents will flock to independent schools. He cites the 44 percent of D.C. public school students now attending charters as a prime example.

And, he adds, “when looking around the country at cities experiencing major education changes driven by high-performing charters, D.C. would barely make a top-10 list.” He is not, however, employing the usual calculation of which cities have the most charter students and the highest charter scores. Instead, he praises cities with the most cooperation between charters and traditional schools. High on that list are Memphis, San Antonio, Denver and San Francisco. He lauds D.C. Schools Chancellor Kaya Henderson for “talking like a charter leader, proposing to send her teachers out for home visits, a strategy used by most top charter schools.”

The Spring Branch district in Texas is praised by Whitmire because superintendent Duncan Klussmann lured Witney from KIPP to be executive director of strategic initiatives and innovation. Witney’s job is to bring in effective charters and help regular schools reach their level. Spring Branch might be a traditional district, Witney says, but it is full of creative people. That helpful attitude could lead the charter battle into more positive directions.